Heat Health

Staying Healthy in the Heat

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Many parts of the United States are suffering through record high temperatures and heat waves, making heat safety a priority—particularly among older or obese patients, children, and anyone with chronic medical conditions. Primary Issues is pleased to provide you with the following information about heat-related illnesses and a checklist to help you remind patients that prolonged heat exposure is a health risk that can produce serious consequences.

On average, 675 people die from complications related to extreme heat each year in the United States—more than tornadoes, hurricanes, floods, lightning, or any other weather event combined,[1] with people older than 65 accounting for almost half of the cases.[2] Normally, the body cools itself by sweating; as the sweat evaporates, the body releases heat and naturally cools itself down. But under conditions of high humidity and prolonged periods of high temperature, sweat doesn’t evaporate as quickly and the body has less opportunity to cool down. In addition to humidity, other factors that limit the body’s ability to stay cool include old age, youth, obesity, fever, dehydration, sunburn, poor circulation, alcohol, and some prescription drugs (Table 1).[2]

Table 1. Medications Associated With the Development of Heat-related Illnesses[2]

  • Alpha adrenergics
  • Anticholinergics
  • Antihistamines
  • Benzodiazepines
  • Beta blockers
  • Calcium channel blockers
  • Neuroleptics
  • Phenothiazine diuretics
  • Tricyclic antidepressants

Excessive heat and humidity is not just uncomfortable—it can lead to a life-threatening situation. There are three forms of heat-related illness: heat cramps, heat exhaustion, and heat stroke. Know the signs for each of these conditions and what to do if they occur.

Heat Cramps
Heat cramps is the mildest of the heat illnesses, but can progress to heat exhaustion and eventually heat stroke if not relieved.[3]

  • Heat cramps are involuntary muscle contractions, typically in the large muscle groups, caused by failure to replace fluids or electrolytes, such as sodium and potassium
  • Cramps can be relieved with stretching and by replacing fluids and electrolytes
  • Heat cramps can be prevented by maintaining an adequate intake of water, electrolyte replacement drinks, and by eating fresh fruits and vegetables

Heat exhaustion is more serious than heat cramps and is characterized by weakness, extreme fatigue, nausea, headache, and wet, clammy skin.[3]

  • Heat exhaustion results when the body produces more heat than it can dissipate
  • Inadequate fluid intake is a major contributing factor
  • Patients typically present with a temperature of 100.4°F with an increased pulse rate and moist skin
  • Treat heat exhaustion by resting in a cool/shaded environment, by removing clothing so that one’s sweat can evaporate, and by replacing fluids and electrolytes

Heat Stroke
Heat stroke is a medical emergency—brain damage and death may result if treatment is delayed.[4]

  • Heat stroke is a failure of the body’s heat controls. Sweating stops and the body temperature rises
  • Heat stroke is characterized by hot, often dry skin and a body temperature above 104°F, mental confusion, loss of consciousness, convulsions, or even coma
  • The patient may present with sudden collapse and loss of consciousness followed by irrational behavior
  • Although classic teaching describes patients with heat stroke patient as “hot and dry,” recent studies have shown that over 50% of heat stroke patients are sweating heavily; therefore, the hallmark symptom of heat stroke is altered mental status
  • Aspirin or acetaminophen have no effect on environmentally induced hyperthermia and are contraindicated
  • Whereas heat cramps and heat exhaustion may be treated locally, patients with heat stroke should be immediately transported to a hospital and will likely require at least 24 hours of hospitalization


Here are some tips from the Centers for Disease Control and Prevention and the American Red Cross to help patients avoid the consequences of overheating.[1,5]

Stay hydrated. Excess heat causes excess fluid loss, which leads to a decrease in sweating. Drink plenty of cool fluids, even if you don’t feel thirsty. Avoid drinks with caffeine or alcohol, as they cause additional fluid loss. Eat small meals and eat more often. Outdoors, drink bottles of water that have been frozen overnight; they will stay cool as they thaw. During hot weather, people need to drink more liquid than thirst indicates. Increase your fluid intake, regardless of your activity level. During heavy exercise in a hot environment, folks should drink two to four glasses (16-32 ounces) of cool fluids each hour.

Stay cool. Air conditioning is the best protection against heat-related illnesses. If you don’t have access to air conditioning at home or work, choose places you could go for relief from the heat during the warmest part of the day (schools, libraries, theaters, malls).

Dress comfortably. Wear loose-fitting, lightweight, light-colored clothing. Avoid dark colors because they absorb the sun’s rays.

Play nicely. Slow down, stay indoors, and avoid strenuous exercise during the hottest part of the day. Postpone outdoor games and activities. If leading organized activities, follow established guidelines from schools, sports organizations, or medical organizations regarding changing or canceling activities to prevent heat illness, and alter practices to remove the need for heavy safety gear (eg, football pads) on hot or humid days.

Slow down. Take frequent breaks if you must work outdoors, and use a buddy system when working in excessive heat. Take water breaks frequently.

Be sun smart. Who should wear sunscreen? Everyone![6] Sunburn affects the body’s ability to cool itself and causes a loss of body fluids. Protect yourself from the sun by wearing a wide-brimmed hat—which also keeps you cooler—and sunglasses. Wear a sunscreen of at least SPF 30 marked “broad spectrum” or “UVA/UVB protection” 30 minutes prior to going out. Continue to reapply it accordingly.

Check in. Check on family, friends and neighbors who do not have air conditioning, who spend much of their time alone or who are more likely to be affected by the heat. Never leave children or pets alone in enclosed vehicles. Check on pets frequently to ensure they have enough water and are not suffering from the heat.


Jill Shuman, MS, ELS
Published on August 9, 2011



  1. Media Advisory: CDC urges: stay cool to stay healthy as temperatures soar. Centers for Disease Control and Prevention Website. http://www.cdc.gov/media/releases/2011/a0725_staycool.html. Published July 25, 2011. Accessed August 5, 2011.
  2. Wexler RK. Evaluation and treatment of heat-related illnesses. Am Fam Physician. 2002;65(11):2307-2314.
  3. Becker JA, Stewat LK. Heat-related illness. Am Fam Physician. 2011;83:1325-1330.
  4. Bouchama A, Knochel JP. Heat stroke. N Engl J Med. 2002;346(25):1978-1988.
  5. Heat Wave Safety Checklist. American Red Cross. http://www.redcross.org/www-files/Documents/pdf/Preparedness/checklists/HeatWave.pdf. 2009; Stock No. 658529.
  6. Sunscreens. American Academy of Dermatology Website. http://www.aad.org/media-resources/stats-and-facts/prevention-and-care/sunscreens. 2011. Accessed August 5, 2011.