Heat-related health problems, especially among vulnerable populations such as older adults, are soaring as recent record heat from climate change continues across the United States.  Being hot for too long can cause several heat-related illnesses, all grouped under the name hyperthermia (hy-per-THER-mee-uh). Heat is one of the top weather-related causes of death in the U.S., so knowing the signs of hot-weather illnesses and how to prevent them may save a life.

Watch for these signs of hyperthermia:


  • Dizziness – this is a sign of heat syncope, a condition that can happen when you are active in hot weather. If you take a heart medication called a beta blocker or are not used to hot weather, you are even more likely to feel faint. Rest in a cool place, put your legs up, and drink water to make the dizzy feeling go away.
  • Muscle cramps – a painful tightening of muscles in your stomach, arms, or legs can result from hard work or exercise. Though your body temperature and pulse usually stay normal during heat cramps, your skin may feel moist and cool. Find a way to cool your body down. Rest in the shade or in a cool building. Drink plenty of water.
  • Swelling in your ankles and feet – known as heat edema, occurs when excess heat causes the blood vessels to expand, then body fluid moves into the hands or legs by gravity. There is an increased risk if there are other medical conditions that affect the circulation. People visiting hot climates from colder climates may also have an increased risk of heat edema. If edema is present, put your feet up.  If that does not work fairly quickly check with your doctor. 
  • Dehydration -  your body sends many signals to tell you that you are in need of fluids such as dry mouth, dry cough, headache, fatigue, constipation, dark-colored urine, or loss of appetite yet craving sugar.
  • Nausea, weakness, and rapid pulse - this is a sign of heat exhaustion, a warning that your body can no longer keep itself cool. You might also feel thirsty and uncoordinated and may sweat a lot. Your body temperature may stay normal, but your skin may feel cold and clammy. Some people with heat exhaustion have a rapid pulse. Rest in a cool place and get plenty of fluids. If you don’t feel better soon, get medical care. Be careful—heat exhaustion can progress to heat stroke.

Heat Stroke—A Medical Emergency

Heat stroke requires medical attention right away. Older people living in homes or apartments without air conditioning or fans are at most risk. People who become dehydrated or those with chronic diseases or alcoholism are also at most risk. Signs of heat stroke are:

  • Fainting (possibly the first sign) or becoming unconscious
  • A change in behavior—confusion, agitation, staggering, being grouchy, or acting strangely
  • Body temperature over 104°F (40°C)
  • Dry, flushed skin and a strong, rapid pulse or a slow, weak pulse
  • Not sweating even if it is hot

Who Is at Risk?

Heat affects everyone by limiting the body’s ability to cool down.  While everyone is at risk, the elderly, young children, people with certain health conditions are more vulnerable to the heat. Each year, most people who die from hyperthermia are over 50 years old. Health problems that put one at greater risk include:

  • Heart or blood vessel problems
  • Poorly working sweat glands or changes in your skin caused by normal aging
  • Heartlung, or kidney disease, as well as any illness that makes you feel weak all over or results in a fever
  • Conditions treated by drugs, such as diuretics, sedatives, tranquilizers, and some heart and high blood pressure medicines; they may make it harder for your body to cool itself
  • Taking several prescription drugs; ask your doctor if any of your medications make you more likely to become overheated.
  • Being very overweight or underweight
  • Drinking alcoholic beverages

Tips to prevent hot-weather illness:

  • Drink plenty of cool non-caffeinated and non-alcoholic liquids, even when not thirsty, and carry a water bottle with you throughout the day
  • Eat hydrating foods such as vegetables and fruit which are 90% water by weight, and avoid dehydrating foods such as  those with excess protein, salt, and sugar which may cause thirst and metabolic imbalances
  • Wear light-colored, loose-fitting clothes
  • Wear sunscreen outside, as sunburned skin cannot as readily regulate body temperature
  • Shower, bathe, or sponge off with cool water
  • If it's too hot, put off exercising for the time being or try exercising indoors
  • If you have to be outside, let yourself acclimate to the heat and take frequent breaks in a cool, shady place
  • If you live in a home or apartment without fans or air conditioning, try to keep your house as cool as possible by limiting your use of the oven, and keeping your shades, blinds, or curtains closed during the  hottest part of the day (but open your windows at night). 

    f you cannot effectively cool your home look up cooling centers, which are air-conditioned places where you can cool off in the summer. You can find one closest to where you live by checking out the National Center for Healthy Housing. Going to the movies, having lunch at a restaurant, visiting your local library, or shopping at an indoor mall are also good ways to pass the time in safe, air conditioned comfort.

    It’s really important to check on friends or neighbors without sufficient cooling in their home, especially if they are in a high risk category, and make sure that they have the ability to take care of themselves.  If they are in danger provide them cool drinks and invite them into your home or take them to an air-conditioned spot to cool down.  If they already show signs of heat distress and illness get them to a clinic or emergency room.