Clinical Research Directory

Testing Interventions to Mitigate the Health Impact of Heatwaves on Primary School Children in Climate-vulnerable Districts of Bangladesh.

The goal of this clinical trial is to assess the impact of implementing a combination of heat education and school-based physical infrastructure interventions in reducing heat related illnesses and improving educational outcomes among primary school children aged 7-14 years in two climate-vulnerable districts of Bangladesh. The main questions it aims to answer are: Whether different combinations of heat education and physical infrastructure interventions can reduce indoor classroom temperatures and heat-related illnesses and improve the health and mental well-being of primary school children. Whether these interventions can improve educational outcomes among primary school children and provide cost-effective and scalable solutions for heat mitigation in low-resource settings. Researchers will compare different combinations of interventions, including: (1) heat education with solar reflective paint, (2) heat education with bamboo ceiling and polyethylene foam, and (3) heat education with both solar reflective paint and bamboo ceiling with polyethylene foam, to assess their relative cost-effectiveness. The interventions will be implemented in BRAC Education Programme-run primary schools in Gaibandha and Kurigram districts. Children will be the primary participants of the study. Researchers will assess changes in classroom indoor temperature, heat-related health outcomes and mental well-being among children, as well as their school attendance and academic performance. The study will also explore potential scalability of the interventions in similar settings.

Efficacy of Electric Fans in Children During Heat Waves

Extreme heat exposure is an escalating global public health concern, with climate change driving increases in the frequency, duration, and intensity of heat events. Projections indicate substantial increases in heat-related morbidity and mortality in the coming decades, including among children and youth, who are increasingly recognized as a physiologically vulnerable population. The purpose of this project is to evaluate the effectiveness of commonly used heat-mitigation strategies, specifically midday access daylong electric fan use, in reducing physiological strain and maintaining cognitive function, perceptual comfort, and psychological well-being in children and youth exposed to prolonged indoor heat. The study also aims to determine whether these strategies provide comparable protection in children and youth relative to young adults. Participants will complete four sessions under the same environmental conditions (31°C and 36°C), with each temperature completed twice: once with continuous electric fan use and once without fan use. The four sessions therefore consist of: (1) 31°C without fan use; (2) 31°C with fan use; (3) 36°C without fan use; and (4) 36°C with fan use.

Consecutive Occupational Heat Exposure With and Without Overnight Cooling

Extreme heat events are becoming more frequent, intense, and prolonged, increasing the risk of heat-related illness among workers exposed to hot environments. Current occupational heat-stress guidelines are designed to limit excessive increases in core body temperature and physiological strain during work in the heat through the use of work-rest schedules. However, these guidelines are largely based on single-day heat exposures and assume that workers recover in cool indoor environments between shifts. During heat events, many workers may instead recover in homes or accommodations that remain overheated, particularly in the absence of air conditioning. Inadequate overnight cooling may impair the body's ability to dissipate heat, increase physiological strain, and reduce tolerance to heat exposure on subsequent workdays. Older adults may be especially vulnerable due to age-related impairments in heat-loss capacity. To date, the effects of recovering in an overheated indoor environment on physiological strain and thermoregulatory function during repeated occupational heat exposure remain poorly understood, limiting the development of evidence-based recommendations to protect workers during prolonged heat events. The primary objective of this study is to determine whether overnight recovery in an overheated indoor environment increases physiological strain during repeated occupational heat exposure in older adults. Specifically, investigators will assess whether recovery at the recently proposed upper indoor temperature limit of 26°C and 45% relative humidity (RH) (PMID: 38329752) is sufficient to attenuate elevations in core temperature during subsequent work in the heat compared with recovery in an overheated indoor environment (31°C, 45% RH) representative of conditions commonly experienced during extreme heat events. Healthy older adults will complete two consecutive days and nights of simulated moderate-intensity occupational heat exposure, with overnight recovery occurring in either the 26°C or 31°C condition. Measures of core temperature, cardiovascular strain, heat-loss capacity, hydration status, sleep quality, cognitive function, mood, and perceptual responses will be assessed to determine the impact of overnight recovery conditions on responses to repeated heat exposure. Whole-body heat-loss capacity will also be evaluated before and after the exposure protocol as assessed during incremental, intermittent exercise protocol performed in an air calorimeter.

Indoor Overheating and Physiological Strain in Older Adults With COPD

During warm weather, homes without air conditioning can stay hot for long periods, and most heat-related health problems in Canada happen indoors rather than outdoors. Health Canada recommends that indoor temperatures not exceed 26 °C in homes occupied by people who are more susceptible to heat. That recommendation is based largely on population-level evidence, and very little is known about how susceptible individuals actually respond, physiologically, when indoor temperatures rise above it. Older adults living with chronic obstructive pulmonary disease (COPD) are among the groups identified as more susceptible to heat. COPD involves persistent airflow limitation, reduced lung and cardiovascular reserve, and altered cellular stress responses. Despite this, no laboratory study has directly measured how adults with COPD respond to a full day spent indoors in warm conditions. This randomized crossover trial will measure how older adults with COPD respond to two different indoor environments, each experienced for eight hours on separate days at least one week apart. One day is spent at the recommended indoor temperature limit and the other at a warmer temperature representative of conditions recorded inside Canadian homes during hot weather. Participants remain seated and rest throughout; no exercise or work is performed. Throughout each day, the research team continuously measures core body temperature, skin temperature, heart rate, and measures blood pressure, lung function, breathlessness, thermal comfort, cognitive performance, and balance at set time points. Blood and urine samples are collected at the start and end of each day. Participants are monitored continuously by trained staff. The results are intended to strengthen the evidence base behind Canadian indoor temperature guidance and to inform recommendations for protecting people living with chronic lung disease during hot weather.

Progressive Heat Exposure and Physiological Strain

Occupational heat-stress guidelines are commonly based on the level of environmental heat exposure and are largely derived from studies conducted under constant environmental conditions. However, outdoor workers are typically exposed to dynamic conditions, with environmental heat often increasing progressively from morning to afternoon. Consequently, workers may experience substantially different patterns of heat exposure across the workday even when average daily heat exposure is equivalent. It remains unclear whether the temporal pattern of heat exposure influences the amount of work that can be performed or the physiological strain experienced during a workday. Understanding these responses is important for determining whether occupational heat-stress guidelines developed under constant laboratory conditions adequately protect workers exposed to progressively changing environmental conditions. The primary objective of this study is to determine whether the temporal pattern of heat exposure influences work performed and physiological heat strain during a simulated occupational workday in healthy middle-aged and older men. Participants will complete two 9-hour simulated workdays consisting of a 4-hour morning work period, a 1-hour lunch break, and a 4-hour afternoon work period. During one trial, wet-bulb globe temperature (WBGT) will remain constant at 28°C throughout the workday, whereas during the other trial, WBGT will progressively increase from morning to afternoon to simulate the changing environmental conditions of a typical hot summer workday. Both trials will have the same mean daily WBGT of 28°C. Participants will perform moderate-intensity treadmill exercise, and measures including total work performed, core temperature, heart rate, and time to the initial stay-time threshold will be assessed to determine whether constant and progressively increasing heat exposures produce different physiological and work-performance responses across the workday.

Ethanol Consumption in the Heat

Climate change has significantly increased the earth's average surface temperature and heat waves have been predicted to increase in frequency, intensity and duration. Extreme heat events have increased the susceptibility to heat-related illnesses, such as heat exhaustion, heat stroke or death. Heat health action plans have been designed to advertise cooling behaviours to mitigate physiological strain. Heat health action plans suggest avoiding alcohol consumption during extreme heat as it may increase dehydration and impair behavioural or physiological temperature regulation and thermal perception. Regardless of these messages, alcohol sales continue to remain high during the summer months year after year, and 1/5 of adults identify alcohol as a hydration strategy during extreme heat events. A recent scoping review investigating the effects of alcohol and heat has demonstrated that acute alcohol consumption does not negatively influence thermoregulation, hydration, or hormone markers of fluid balance in the heat compared to a control fluid (https://doi.org/10.1186/s12940-024-01113-y). Further, alcohol consumption may elicit sex- and age-specific alterations in physiological and perceptual responses, neither of which have been explored. Therefore, this study aims to comprehensively evaluate how alcohol consumption systematically alters physiological responses and perceptions during conditions similar to those experienced indoors during extreme heat events in younger and older adults.

Exercise Intensity and Heat Responses in Children and Youth

Little is known about how children and youth regulate body temperature during exercise in the heat compared with young adults, including whether differences in whole-body heat exchange contribute to their responses. The goal of this clinical trial is to determine how exercise intensity affects thermoregulation in boys and girls aged 9-16 years compared with young adult men and women aged 20-25 years. Participants will complete three study visits in a hot environment of 36°C (degree Celcius (97°F, degree Farenheit)), performing light-, moderate-, and vigorous-intensity exercise corresponding to metabolic heat production of 120, 160, and 200 W/m² (w=watts, m=meter), respectively. During each visit, participants will complete four 15-minute bouts of exercise (i.e., bout 1, 2, 3 and 4 respectively) separated by 15-minute rest periods. Testing will be performed in a whole-body air calorimeter, a specialized chamber that precisely measures heat lost through evaporation and dry heat exchange and the amount of heat stored in the body. These measurements, together with core temperature and heart rate, will allow researchers to determine how increasing exercise intensity affects the body's ability to lose heat and whether these responses differ between children and youth and young adults.

Ambient Temperature and Thermoregulation During Exercise in Children and Youth

Little is known about how children and youth regulate body temperature during exercise across different environmental temperatures compared with young adults, including whether differences in whole-body heat exchange contribute to their responses. The goal of this clinical trial is to determine how ambient temperature affects thermoregulation during exercise in boys and girls aged 9-16 years compared with young adult men and women aged 20-25 years. Participants will complete four study visits at ambient temperatures of 22°C (Celsius; 72°F, Fahrenheit), 26°C (79°F), 31°C (88°F), and 36°C (97°F), while exercising at the same moderate-intensity metabolic heat production of 160 W/m² (W = watts, m = meters). During each visit, participants will complete four 15-minute periods of exercise (exercise bouts 1, 2, 3 and 4 respectively) separated by 15-minute rest periods. Testing will be performed in a whole-body air calorimeter, a specialized chamber that precisely measures heat lost through evaporation and dry heat exchange and the amount of heat stored in the body. These measurements, together with core temperature and heart rate, will allow researchers to determine how increasing ambient temperature affects the body's ability to lose heat and whether these responses differ between children and youth and young adults.

Impact of Extreme Heat on Myocardial Blood Flow and Flow Reserve in Young and Older Adults

Extreme heat causes a disproportionate number of hospitalizations and deaths in older adults relative to any other age group. Importantly, many hospitalizations and deaths are primarily due to cardiovascular events such as myocardial infarction. Previous data indicate that older adults have attenuated skin blood flow and sweating responses when exposed to heat, resulting greater increase in core body temperature. Despite these observations, relatively little is known about the risk for myocardial ischemia potentially contributing to the aforementioned higher morbidity and mortality in older adults during heat waves. The broad objective of this work is to determine the impact of ambient heat exposure on myocardial blood flow and flow reserve in young and older adults. Aim 1 will test the hypothesis that older adults exhibit attenuated myocardial flow reserve compared to young adults during heat stress. Aim 2 will determine if the percent of maximal myocardial flow reserve (assess via vasodilator stress) during heat exposure is higher in older adults compared to young adults. The expected outcome from this body of work will improve our understanding of the consequences of aging on cardiovascular responses to ambient heat stress.

Working in the Heat at Simulated Altitude: Effects of Normobaric Hypoxia on Physiological Strain

Extreme heat events are becoming more frequent, intense, and prolonged, increasing the risk of heat-related illness among workers performing physically demanding work in hot environments. Occupational heat-stress guidelines use work-rest schedules to limit increases in core temperature and physiological strain, but they do not clearly define the safe maximum duration of continuous work before heat-mitigation controls should begin, known as the initial stay time. Recent work has generated initial stay time recommendations for young and older workers performing moderate-intensity work in the heat; however, these recommendations were developed under normoxic conditions. In many workplaces, heat may occur alongside additional stressors such as hypoxia, including work at altitude or in oxygen-reduced environments. Hypoxia can increase cardiovascular strain, reduce arterial oxygen saturation, and impair exercise tolerance, potentially compromising heat-stress guidance developed under normal oxygen conditions. Older workers may be especially vulnerable because of age-related reductions in thermoregulatory and cardiovascular function. It remains unclear whether hypoxia increases physiological strain during work in the heat or whether current initial stay time and recovery recommendations remain protective under combined heat and hypoxic stress. The primary objective of this study is to determine whether hypoxia increases physiological strain during moderate-intensity work in the heat in young and older males. Specifically, the study will assess whether normoxia-derived initial stay times and recovery recommendations for work at 29°C wet-bulb globe temperature (37.5°C, 35% RH) remain effective during exposure to 14% inspired oxygen, simulating approximately 3000 m altitude. Healthy young and older males will complete two simulated occupational heat exposures: heat alone and heat plus hypoxia. Participants will perform moderate-intensity treadmill work based on age-specific initial stay times, followed by prescribed work-rest cycles and seated recovery. Core temperature, cardiovascular strain, oxygen saturation, skin temperature, hydration status, perceptual responses, mood, environmental stress symptoms, and cognitive function will be assessed to determine whether hypoxia modifies responses to work in the heat. Findings will help determine whether occupational heat-stress guidance requires refinement for workers exposed to combined heat and hypoxic stress.

Suitability of a 26 °C Indoor Environment for Mitigating Heat Strain in Young Adults

While an indoor upper temperature limit of 26 °C has been shown to protect heat-vulnerable older adults (DOI: 10.1289/EHP11651), this guideline has not been verified in young, habitually active adults. Public health recommendations during hot weather typically emphasize staying in cool environments, avoiding strenuous activity, wearing lightweight clothing, and maintaining adequate hydration. However, young adults may be less likely to follow these guidelines. They often do not reduce their physical activity during extreme heat events and may overdress for fashion, cultural, or religious reasons. These behaviors can impose an additional thermoregulatory burden and lead to greater physiological strain during heat exposure, even though young adults generally have a higher capacity for heat dissipation than older individuals. Accordingly, it is important to evaluate whether an indoor temperature limit of 26 °C is sufficient to protect young, habitually active adults. To address this gap, the investigators aim to assess changes in body temperature and cardiovascular strain in young, habitually active adults (18-29 years) during an 8-hour exposure to the recommended indoor upper temperature limit of 26 °C and 45% relative humidity (humidex of 29, considered comfortable). Participants will complete two conditions: A) seated rest while dressed in light clothing (T-shirt, shorts, and socks), and B) light exercise (stepping to simulate activities of daily living, 4-4.5 METs) performed once per hour (except for the lunch hour) while dressed in light clothing plus an additional insulating layer (sweatshirt and sweatpants). This experimental design will allow investigators to determine the effects of added clothing insulation and light activity-representative of typical daily behaviors-on physiological strain in young adults, and to assess whether refinements to the recommended 26 °C indoor temperature limit are warranted for this population.

The Impact of Wearing the Hijab on Whole-body Heat Loss During Exercise-heat Stress

The hijab (headscarf and cloak) is a Muslim dress, which covers the head, neck and chest, and conceals the female hair, leaving the face uncovered. It is worn by Muslim women worldwide including young Muslim women engaging in sports and exercise. As with any clothing worn on the body, the hijab can impact heat dissipation during exercise, potentially leading to increased body temperature and discomfort, especially in warmer environments. However, the extent to which the hijab may restrict heat loss remains unclear. This study aims to assess dry and evaporative heat exchange in young women performing moderate-intensity intermittent exercise in dry heat conditions (40°C, 15% relative humidity).

Carbohydrate or Protein Drinks Before Exercise in the Heat

This project examines whether consuming a high-protein or high-carbohydrate beverage before exercise in the heat impacts metabolism and heat balance during exercise, with the following research questions: 1. Does a high-protein vs. high-carbohydrate pre-exercise drink impact metabolism and body temperature responses during a treadmill walking in the heat? 2. Does a high-protein or high-carbohydrate drink change oxygen use and heat production during treadmill walking in the heat?

Identifying the Limits of Survivability in Heat-exposed Older Females

Climate change increases extreme heat events, elevating global heat-illness risk. Females have reduced heat loss capacity (\~5%) compared to males, driven by differences in skin blood flow and sweating responses. While findings on sex-mediated mortality are mixed, some studies suggest older females (≥65 years), face higher heat-related mortality/morbidity risks, evidenced by disproportionate female deaths in the 2021 Western Heat Dome. The effects of extreme uncompensable heat on older females remain understudied. Heat exposure initially causes net heat gain, raising core/skin temperatures and triggering heat-loss responses. Under compensable heat stress, heat loss balances gain, stabilizing core temperature. Uncompensable heat stress (exceeding maximal dissipation capacity) causes continuous core temperature rise, posing severe health risks. The specific temperature and relative humidity (RH) limits where compensability is lost are critical survival determinants, influenced by age and sex. Ramping protocols identify these limits: participants face progressively increasing heat stress (e.g., staged humidity rises) while core temperature is monitored. Core temperature typically stabilizes initially, then exhibits an abrupt rapid increase at an inflection point, operationally defined as the limit of compensability. Despite increasing use, ramping protocol validity for accurately identifying this threshold remains unverified. This project assesses ramping protocol validity for determining uncompensable conditions in older females and evaluates cumulative thermal and cardiovascular strain, as well as psychological and cognitive responses to both uncompensable and compensable heat. Participants will complete five trials. Trial 1 (Ramping): Rest at 42°C, 28% RH for 70min, then incremental RH increases (3% every 10min) to 70% RH. Individual core temperature (rectal) inflection points are identified from the ramping trial. Trials 2-5 (Fixed Conditions, Randomized): i) \~10% below inflection; ii) \~5% below inflection; iii) \~5% above inflection; iv) Thermo-neutral control (26°C, 45% RH). Comparing the rate of rectal temperature change and cumulative strain during prolonged fixed exposures (especially below vs. above inflection) will validate if the ramping inflection point represents the true limit of compensability for older females.

Efficacy and Safety of Modified ORS(Amr and Khulood ORS) in Diabetic Pilgrims During Hajj

Heat stress and dehydration are significant risks for diabetic pilgrims during the Hajj, often leading to severe complications. Standard Oral Rehydration Salts (ORS) are effective for rehydration but may cause hyperglycemia in diabetic patients due to their glucose content. This study aims to evaluate the efficacy and safety of a modified ORS formula ( Amr and khulood ORS) , specifically designed for diabetic individuals, in maintaining hydration without adversely affecting blood glucose levels. The study will involve a randomized controlled trial comparing the modified ORS (Amr and khulood ORS) with standard ORS among diabetic pilgrims experiencing heat stress. Key outcomes include hydration status, electrolyte balance, and glycemic control.

Effects of Hot Baths Prior or After a Damaging Protocol on Muscle Function and HSP70 Expression

Muscle lengthening contractions lead to physiological responses such as strength loss, soreness, immune cell infiltration, and CK production, along with elevated heat shock proteins (HSPs), which protect and regenerate cells. Passive heating before or after exercise can aid in recovery by restoring strength and reducing soreness, requiring a core temperature of over 38.5°C for 20 minutes to be effective. Studies show that combined mechanical and thermal stress induces a cumulative HSP response, enhancing cellular protection. Thermal stress alone peaks at 16- 24 hours, whereas mechanical stress shows a biphasic response, with peaks at 3-6 hours and around 39 hours. Thus, combining heat with exercise could optimize HSP production, improving recovery by increasing and accelerating the HSP response. However, more research is needed to determine the best timing for thermal stress in human applications, especially in sports and therapy contexts. This study aimed to compare the effects of hot-water immersion administered before versus after muscle-lengthening exercise on muscle function and HSP70 expression in healthy young athletes.

Impact of Indoor Overheating on Physiological Strain in Children

Communities worldwide are experiencing increasing heat extremes that challenge the limits of human thermoregulation, particularly among vulnerable populations such as children. Compared with adults, children are more susceptible to heat related illness due to less efficient thermoregulatory systems and difficulty recognizing early signs of heat stress. In addition, prolonged heat exposure can adversely affect their mental health, contributing to cognitive decline, heightened anxiety, and irritability. As children spend substantial time in hot environments at school and at home, and as these conditions intensify with climate change, actions to safeguard their health are essential. Yet our understanding of heat exposure effects in children remains incomplete, hindering the development of evidence based strategies to protect them. To address this gap, the investigators aim to evaluate whether an indoor temperature limit of 26 °C (45 percent relative humidity), the upper threshold recommended to protect older adults, can effectively prevent dangerous increases in physiological strain and declines in cognitive function in children during a simulated daylong heatwave. The preliminary study will assess physiological and cognitive responses in children aged 10 to 15 years during a 6 hour exposure (approximating a typical school day) to two conditions: (1) the recommended indoor temperature upper limit (26 °C) and (2) a high heat condition representative of homes and schools without air conditioning during extreme heat events (36 °C). In both conditions, children will remain seated at rest while wearing light clothing (t shirt and shorts), with the exception of performing 15 minutes of stepping exercise (6-6.5 METS) each hour (excluding the lunch period) to reflect typical daily activity in a school setting. This experimental design will allow investigators to determine whether maintaining indoor temperatures at the recommended upper limit for older adults sufficiently mitigates physiological strain in children.

Suitability of the 26 °C Indoor Temperature Upper Limit for Older Adults: Impacts of Clothing and Daily Activity

While an upper limit of 26°C has been shown to be protective for heat-vulnerable older occupants (DOI: 10.1289/EHP11651), this recommendation did not consider the added heat burden associated with increases in internal heat production accompanying activities of daily living or the restriction to heat loss caused by clothing insulation. To safeguard the health of older adults, health agencies worldwide recommend the remain in cool space indoors, avoid strenuous activity, wear lightweight clothing, and drink cool water regularly throughout the day. However, older adults do not sense heat as well as their younger counterparts. Consequently, they may not take appropriate countermeasures to mitigate physiological strain from indoor overheating. This may include overdressing despite high indoor temperatures. In other cases, individuals may wear insulated clothing in hot weather to observe cultural or religious modesty requirements, which serve as expressions of faith and identity rather than a tool for thermoregulation. Further, individuals may be unaware of the consequences of increases in physical activity on heat gain and may therefore not adjust their normal day-to-day activity levels to prevent potentially dangerous rises in body temperature. Consequently, this may necessitate a lowering of recommended upper indoor temperature limit during hot weather. To address these important considerations, on separate occasions the investigators will assess the change in body temperature and cardiovascular strain in older adults (65-85 years) exposed for 8 hours to the recommended indoor temperature upper limit of 26°C and 45% relative humidity equivalent humidex of 29 (considered comfortable) while they A) perform seated rest dressed in light clothing (t-shirt, shorts and socks), B) perform light exercise (stepping exercise to simulate activities of daily living, 4-4.5 METS) every hour (except during lunch hour period) dressed in light clothing, C) perform light exercise (4-4.5 METS) every hour (except during lunch hour period) dressed in light clothing (t-shirt, shorts and socks) and an added clothing layer (sweatshirt and sweatpants) and D) perform seated rest dressed in light clothing (t-shirt, shorts and socks) and an added clothing layer (sweatshirt and sweatpants). With this experimental design, investigators will assess the effects of added clothing insulation and light activity, representative in activities of daily living on physiological strain and identify whether refinements in the recommended 26°C indoor temperature limit may be required.

Heat Stress in Individuals With Schizophrenia

Schizophrenia is a severe mental illness affecting approximately 24 million people worldwide and is associated with more than double the all cause mortality risk of the general population. Emerging evidence demonstrates that elevated temperatures acutely worsen mental health symptoms and significantly increase the risk of heat related morbidity and mortality. For people living with schizophrenia, prolonged exposure to heat can exacerbate psychiatric symptoms, impair judgment and decision making, and reduce the ability to engage in protective behaviors such as increasing hydration, reducing clothing, improving ventilation, or seeking cooler environments. As a result, individuals with schizophrenia may experience higher rates of heat related illness. To date our understanding of heat exposure effects in individuals with schizophrenia remains incomplete, hindering the development of evidence-based strategies to protect them. Thus, the primary objective of this exploratory study is to gather preliminary data on the effects of indoor overheating on physiological responses (core body temperature and cardiovascular function), cognitive performance (attention, working memory, and reaction time), and mood in adults with schizophrenia. Specifically, we will assess whether maintaining indoor conditions at the upper recommended temperature limit for older adults (26°C, 45% relative humidity \[RH\]; PMID: 38329752) is sufficient to mitigate physiological strain compared with exposure to a hot indoor environment (36°C, 45% RH) representative of non-air-conditioned homes during extreme heat events in individuals with schizophrenia. In both conditions, the individual will remain seated at rest while wearing light clothing (t shirt and shorts), with the exception of performing 15 minutes of stepping exercise (4-4.5 METS) each hour (excluding the lunch period) to reflect typical daily activities of daily living.

Implementing an Intervention to Reduce Heat Stress and Chemical Exposures

The investigators are studying the dangers that farmworkers face while working in the fields and at home. The investigators goals are: 1. Measure how much heat and chemicals farmworkers in Imperial County are exposed to. The investigators will ask the participants to wear a special belt under their clothes during work to measure heat. The investigators will also put two small temperature monitors in the participant's home for a day. The investigators will collect a urine sample to check hydration, and also measure the participants height, weight, blood pressure, and some blood markers for diseases using a simple finger-prick test. To measure chemicals, the investigators will give the participants a wristband to wear for a week and hang another in the participants home. The investigators will also collect dust from each participant's home with a vacuum. Then, the investigators will analyze everything at San Diego State University. After collecting samples, a trained community health worker will ask the participants a few questions about their work, lifestyle, health symptoms, and any hazards they face. The investigators will meet the participants twice at their homes to distribute the tools which will later be collected. Once the tools are collected, the investigators will have the chance to follow up with the participants if they have any questions. 2. Provide help to lower heat and chemical exposure with the help of community health workers. 3. Measure heat and chemicals again using the same methods to see if the project made a difference. 4. Talk to participants about what they liked and how the investigators can make future projects better.

Title: ICARUS - Psycho-physiological Profiling of Low and High Heat-resilient Individuals

The escalating environmental heat-stress associated with global warming is a societal challenge with large and potential harmful consequences for humans. Excess morbidity and mortality during heat waves provides strong evidence for fatal outcomes. However, it is unclear why some people are particularly vulnerable and get sick from hyperthermia, while others adapt and tolerate exposure. The Icarus project aims to provide a psycho-physiological framework for improved mitigation of the health threats associated with global warming. Combining expertise in integrative thermal physiology, pharmacology, photobiology, psychology and machine learning, we will collaborate on comprehensive cross-scientific studies using controlled lab-exposure combined with investigations in ecological settings including vulnerable and highly tolerant people across populations from northern to southern Europe. Advanced algorithms will be developed to generate personalized alerts and advising based on behavioral patterns, psychological profiling, predicted vulnerability and willingness to adopt resilience-building strategies. Global warming is projected to continue towards the end of the 21st century and constitutes an increasing threat to human health unless we as individuals and collectively become better in preventing acute effects, as well as devise sustainable strategies to limit further anthropogenic warming of the climate system. Acutely, improved guidance is important for both individual and public health, where Icarus aims at providing a highly improved basis for preventing heat-related disease, advising or nudging people towards pro-health behavior, including smarter use of technologies to mitigate heat stress, or adjusting medication to reduce adverse effects during heat events. In support of the sustainability agenda, our framework also forms a novel basis for developing advising algorithms relevant for optimization of climate change mitigation policy-making.

Indigenous Nutritional Supplements for Pregnancy to Improve Resilience in Environmental Heat

The purpose of this study is to learn whether a simple, traditional, and balanced meal made from local foods, eaten once a day during pregnancy, can help women in rural Pakistan stay healthier in hot weather and give birth to healthier babies. Climate change has made heat a serious challenge for pregnant women, especially in areas with limited resources. This study will explore whether an indigenous meal that is culturally acceptable and easy to prepare can improve resilience to heat stress and support better outcomes for both mothers and newborns. The study will focus on two main questions: * Can this daily balanced meal reduce the harmful effects of heat stress during pregnancy? * Does it improve newborn health, especially birth weight? Researchers will compare women who eat the balanced local meal every day with women who continue their usual meals. They will check changes in women's health, levels of key vitamins and nutrients, and their babies' birth outcomes. During the study, participants will: * Either eat the balanced local meal daily or continue their usual meals. * Share information on their health, diet, and heat exposure. * Provide small samples, such as blood and stool, to study nutrient levels and gut health. * Have their newborns' health and growth measured at birth.

Heat Stress Exposure Among Low-Income Residents in Bangladesh and Evaluation of Indoor Interventions

The goal of this clinical trial is to learn if infrastructure and equipment installed to cool homes reduce adverse health outcomes. The main questions it aims to answer are: What is the impact of the intervention on indoor heat stress? What is the impact of the intervention on personal exposure to heat stress? What is the impact of the intervention on health outcomes, including heart rate, and heart rate variability, and sleep quality? Participants will have cooling infrastructure and/or equipment installed in their home; have heat stress sensors installed inside and outside their home and wear personal heat stress monitors; allow some biological functions such as heat rate, heat rate variability, and sleep quality.

Beat the Heat Boston

The goal of this stepped wedge trial is to assess the practical effects of air conditioners on hot weather impacts among older adults. The main questions it aims to answer are: How does the presence of an air conditioning unit affect heat stress, heat strain, mental health, and healthcare utilization among older adults who did not previously have access to air conditioning? How, and in what conditioners, do older adults use air conditioning once it is installed in their home? Researchers will compare participants in arms with (A) and without (B) air conditioning units in the first summer season; this will allow them to assess the effect of air conditioners. In the second summer season, both arms will have air conditioning units, but those in the year two distribution arm (B) will receive an electricity subsidy, while those in the year one AC distribution arm (A) will not, allowing researchers to assess the effect of an electricity subsidy. Participants will be randomized to receive an air conditioner and financial support for electricity costs in either the first summer season or the second summer season of the study. * Heat stress, heat strain, mental health, and healthcare utilization will be assessed via participant survey. * Air conditioner utilization will be assessed via continuous load monitoring devices. * Indoor air temperature will be assessed via continuous data loggers.