An Ounce of Caution Prevents Heat-Related Illness
After a few quick stretches, you head out on the tennis court for the first match of the summer. After a solid serve, you rush the net. Suddenly, your leg freezes in a cramp, and you fall down in pain—a victim of the heat. The four most common heat-related emergencies are cramps, fainting, exhaustion, and heat strokes. A fifth, heat injury, is similar to heat stroke but without symptoms of central nervous system (CNS) dysfunction. These illnesses occur when the body can no longer cool itself properly.
Heat-related illnesses may be fatal in extreme cases, but are fortunately preventable, according to the CDC.
Older adults, infants and children, people with certain medical conditions, those who work in hot environments, and athletes are at greatest risk for injury. When weather forecasters talk about a heat index of 90 degrees or above—that's the temperature in the shade—everyone should take extra precautions.
High humidity and high air pollution increase the risk of heat-related illnesses.
Evaporation of sweat keeps the body cool. When you can no longer sweat or your sweat can't evaporate because of high humidity, you can no longer dissipate heat and your body temperature may rise. When the body temperature increases too much, most people experience headache, dizziness, muscle weakness, cramps, or nausea. This is called hyperthermia. If body temperature goes too high or hyperthermia persists too long, collapse and death may follow.
Take time to prepare
Heat-related illnesses can be prevented by gradually acclimating to increasing temperatures. Athletes and exercisers should begin with sessions at 50 percent of their performance level in the month before beginning competition or regular exercise.
According to the CDC, there are several rules of thumb for exercising and drinking fluids. If you exercise in the heat for an hour, you should drink water at least 15 minutes before exercising and every 15 minutes during exercise. For exercise lasting longer than 60 to 90 minutes, athletes should drink a commercial carbohydrate and salt replacement fluid.
This is a form of muscle spasm and tightening that occurs as a result of intense exercise in the heat. It could be caused by a lack of sodium and fluids. Treatment: Rest, cool down, stretch, and drink rehydrating solutions.
Heat syncope (fainting)
This is caused by dehydration and sudden cessation of exercise. Treatment: Drink fluids and lie down in a cool place with your feet elevated. To avoid heat syncope, gradually end your workout with a cool-down activity like slowly walking or pedaling a bicycle.
Symptoms of heat exhaustion are exhaustion, weakness, feeling faint, excessive sweating, hot, red skin, elevated core body temperature (less than 104 degrees Fahrenheit or 40 degrees Celsius), decreased urine, and disorientation. Other symptoms include heat cramps, headache, rapid heartbeat, fainting, muscle aches, vomiting, and diarrhea. Treatment: Rest, cool down rapidly with fans and ice packs, and drink fluids. IV fluids may be needed. Seek further medical attention if necessary.
Heat stroke is a medical emergency. Heat stroke occurs when the body loses its ability to regulate its core body temperature through sweating. The most telling signs of heat stroke are an elevated core body temperature (greater than 104 degrees Fahrenheit or 40 degrees Celsius) and CNS dysfunction. Other signs and symptoms include rapid heartbeat, shallow breathing, lack of sweating, hot, flushed dry skin and mental impairment ranging from confusion and hysteria to loss of consciousness and coma. Treatment: Hospital emergency treatment, including removal of excess clothing and cooling the body with ice or fans. CPR, oxygen, and IV fluids may also be needed. While awaiting emergency treatment, use any available means of cooling the body including immersion in water, spraying with water, fans, or other techniques.
How to stay cool in extreme heat
Follow these tips to help you stay cool:
When outside, wear a hat and stay in the shade as much as possible. Avoid asphalt and pavement, if possible. They're normally hotter than dirt or grass, and they radiate infrared heat.
Drink plenty of water before any activity. For strenuous exercise, drink water or a salt replacement fluid about every 15 minutes. If you have pale, clear urine, you're drinking enough fluids.
Schedule strenuous outdoor activity for the cooler parts of the day. Normally, this is before 10 a.m. and after 6 p.m.
At the beginning of the warm weather season, spend several days acclimatizing yourself to the heat by gradually increasing your activities outside.
If you're on any medications, consult with your doctor before undertaking any strenuous activity in the heat. Some drugs can cause dehydration.
Wear light-colored, loose-fitting clothes. Natural fibers like cotton help the body release heat better.
Eat light foods, as well as plenty of fruits and vegetables, because they contain water.
Take cool or tepid baths and showers to cool down.
Avoid alcohol and caffeine, which can interfere with sweating and fluid loss.
Simplify meal preparation to cut down on cooking time. Use a microwave if possible.
If your home doesn't have air conditioning, use fans to circulate the air. Spend as much time as possible in air conditioned buildings, such as libraries or shopping malls.
- Hanrahan, John, MD
- Weisbart, Ed, MD