The summer of 2024 is likely to be one of the hottest on record in the U.S, and July was earth’s record hottest month. Extreme heat is dangerous for human health, including mental health, researchers at the Yale School of Public Health (YSPH) have said. As climate change leads to record-breaking temperatures, it’s important to know how to stay safe amidst the climbing temperatures.
How to cope with extreme heat
- Extreme heat can lead to heat cramps, heat exhaustion, heat stroke, and death. Be aware of the signs and symptoms, including, but not limited to, dizziness, nausea, and confusion.
- Cool off by seeking shelter in an air-conditioned building (if possible), sip water (except in the case of heat stroke), place cool/wet cloths on the skin, and wear loose, cooling clothing. Call medical personnel if the symptoms persist, vomiting occurs, or if heat stroke is suspected.
- Fans should only be used if the heat index temperatures are below 90 degrees Fahrenheit as they can otherwise result in making an individual hotter.
Make sure to contact your health care provider or seek medical attention if you are concerned that you have a heat-related illness.
Extreme heat and mortality
Over the past few years, deaths resulting from extreme heat have been on the rise, with more than 2,300 attributed deaths in the U.S. in 2023. Extreme heat is defined by two or more days of high temperatures and humidity exceeding 90 degrees Fahrenheit.
When sweating is no longer a sufficient means to cool the body down during high-temperature and high-humidity days, individuals can suffer from heat-related health problems. Some of the risk factors that could lead to an increased risk for heat-related illness include, but are not limited to, obesity, dehydration, heart disease, and mental illness. Air-conditioned buildings can help beat the heat. Communities have set up cooling centers for public use, such as in Washtenaw County, Michigan, New York City, and New Haven.
Heat cramps, heat exhaustion, and heat stroke
Extreme heat can lead to several different conditions, including heat stroke, a medical emergency that requires immediately cooling down the person's body in cold water.
- Heat stroke (intense headache, confusion, fast pulse, body temperature exceeding 103 degrees Fahrenheit, nausea)
- Heat stroke is a medical emergency and you must call 911 and seek immediate medical attention. Cool the body down by immediately immersing it in cold water.
- When observing athletes, look for signs and symptoms that may indicate that they are suffering from Exertional Heat Stroke.
- Heat cramps (muscle cramps and/or spasms, heavy sweating)
- This can be the first sign of heat-related illness. Watch out for symptoms that progress toward heat exhaustion or heat stroke, listed below.
- Apply pressure or massage the cramps and/or spasms. Provide sips of water as long as the person is not nauseous. If cramps persist for more than an hour, seek medical attention.
- Heat exhaustion (heavy sweating, weakness, pale and clammy skin, dizziness, nausea, thirst.
- Attempt to cool the body down with air conditioning, cool clothes, etc. Provide sips of water. If symptoms persist for more than an hour or if vomiting occurs, seek medical attention.
Extreme heat also can result in increased hospitalization for heart disease-related conditions; worsened asthma and COPD from heat-related ground-level ozone formation; dehydration and related kidney injuries, and mental health complications and behavioral changes.
Extreme heat impacts mental health, too
“Research has consistently shown links between extreme heat and adverse mental and behavioral health outcomes, including depression, suicidality, and aggression,” said Sarah Lowe, associate professor of public health (Social and Behavioral Sciences.
"As global temperatures rise, it is increasingly critical to identify pathways from heat to poor mental health. These could include the onset or worsening of physical health outcomes, disruptions to health behaviors like outdoor exercise, and decreased access to outdoor spaces and activities that provide a sense of connection and community. Mitigation efforts should account for the potential of extreme heat to exacerbate health disparities, including those related to mental health," Lowe added.
The effects of extreme heat include:
- Irritability
- Depression
- Suicide
- Behavioral changes (i.e. aggression, violence, and and substance use)
- Memory and attention complications
- Sleep difficulties
- Increased risk of dementia-related hospitalization
- Impaired temperature regulation while taking certain antidepressants or antipsychotics
Who is at the highest risk for heat-related illness?
- Workers with routine exposure to outdoor weather conditions
- Individuals with chronic and mental health conditions
- Individuals taking certain medications, such as diuretics, antihistamines, antipsychotics, etc.
Adjusting to hotter environments is possible through the physiological adaptation known as acclimatization, which requires gradual increases in heat exposure over weeks.
Health Safety Tips
- Keep your house cool in extreme heat. Stay indoors in an air-conditioned building such as a community cooling station
- Wear cooling clothing for extreme heat
- Stay hydrated (opt for water and avoid high sugar options)
- Check on your neighbors and loved ones
- Do not leave children, adults, or pets inside vehicles
YSPH studies climate change and health
From developing a heat vulnerability index that reveals which neighborhoods in the U.S. are most vulnerable to heat, to studying how population aging is expected to substantially amplify future heat- and cold-related deaths, YSPH contributes innovate research to address the public health challenge of climate change.
- A team of researchers has developed a metric to gauge heat vulnerability inequities at the census-tract level and created a color-coded interactive map for public use.
- Heat-related deaths can be attributed to population aging.
- The article, Residential and Race/Ethnicity Disparities in Heat Vulnerability in the United States, was recently recognized as one of the top ten most-cited papers. YSPH authors of the GeoHealth article are Mitchell Manware, Robert Dubrow, Daniel Carrión, Yiqun Ma, and Kai Chen.
If you or someone you know is in need of support, reach out to one of the following organizations:
- National Alliance on Mental Illness (NAMI) Teen & Young Adult Helpline: 1-800-950-NAMI (6264)
- Substance Abuse and Mental Health Service Administration (SAMHSA) National Helpline: 1-800-662-HELP (4357)
- Suicide & Crisis Lifeline: 988