Humans, who are warm-blooded beings, maintain their body temperature within a narrow range (within 1 or 2 degrees of 98.6°F) despite large fluctuations in external temperatures.
“This internal temperature range must be maintained for the body to function normally,” notes The Merck Manual of Medical Information. “Body temperature that gets too high or too low can result in serious injury to organs or death.”
A beautiful, sunny day during summer can bring with it loads of fun and excitement. But it can also carry life-threatening illness. Heat sickness is a fast-acting, dangerous killer. Examples include heat cramps, heat exhaustion and heatstroke.
Heat cramps, which can be uncomfortable but not life-threatening, are caused by muscle contractions in both the gastronomies or hamstring area (back of calves). Feeling most like a severe muscle pull, heat cramps are forceful and painful. Heat cramps are associated with lack of fluids, high temperatures and lack of physical conditioning. They can be treated with water, cool air and rest.
Heat exhaustion is exactly what it sounds like: severe exhaustion caused by extreme body heat. Excessive heat and dehydration can cause the body to overreact, thus raising your body temperature to over 102 degrees.
Unlike heat cramps, heat exhaustion is a serious illness and should be carefully monitored. Cool, shady environments, liquids, cool rags placed on various areas of the body and replacement of electrolytes (such as those found in sports drinks) are used to treat this condition. If body temperature remains elevated even after treatment, it’s best to consult your doctor for further information and instruction.
Heatstroke, on the other hand, is considered the most severe form of heat-induced illness. In fact, it is a medical emergency. “Heatstroke can kill or cause damage to the brain and other internal organs,” says the web site of WebMd.org. “Although heatstroke mainly affects people over age 50, it also takes a toll on healthy young athletes.”
There are two features that distinguish heatstroke from other heat disorders: body temperature is higher than 104°F, and symptoms of brain damage develop. “Heatstroke often occurs as a progression from milder heat-related illnesses such as heat cramps, heat syncope (fainting), and heat exhaustion,” WebMd claims. “But it can strike even if you have no previous signs of heat injury.”
According to the Merck Manual, heatstroke occurs because the body cannot lose heat rapidly enough in extreme heat. “Because the body cannot cool itself, body temperature continues to rise rapidly to dangerously high levels,” it points out.
Oftentimes, fainting is the first sign of heatstroke. Other symptoms may include: throbbing headache; dizziness and light-headedness; lack of sweating despite the heat; red, hot and dry skin; muscle weakness or cramps; nausea and vomiting; rapid heartbeat, which may be either strong or weak; rapid, shallow breathing; behavioral changes such as confusion, disorientation or staggering; seizures; and unconsciousness.
“During heatstroke, the skin becomes hot, flushed and dry,” the Merck Manual informs. “Sweating may not occur despite the heat. A person may become confused and disoriented and may have seizures or lapse into a coma. The heart rate and breathing rate increase. The pulse rate is usually rapid. The blood pressure may be high or low.”
Medical experts say that if you suspect someone has a heatstroke, immediately call the emergency hotline or transport the person to a hospital. Any delay seeking medical help can be fatal.
But while waiting for the paramedics to arrive, you have to initiate first aid. Here’s what WebMd suggests: Move the person to an air-conditioned environment—or at least a cool, shady area—and remove any unnecessary clothing. If possible, take the person’s core body temperature and initiate first aid to cool it to 101° to 102°F. If there is no thermometer available, don’t hesitate to initiate first aid.
WebMd also suggests these cooling strategies: (1) Fan air over the patient while wetting his or her skin with water from a sponge or garden hose. (2) Apply ice packs to the patient’s armpits, groin, neck and back. Because these areas are rich with blood vessels close to the skin, cooling them may reduce body temperature. (3) Immerse the patient in a shower or tub of cool water, or an ice bath.
After a person recovered from heatstroke, he or she will probably be more sensitive to high temperatures during the following week. So it’s best to avoid hot weather and heavy exercise until the doctor tells him or her that it’s safe to resume his or her normal, activities.
“Heatstroke typically develops in older, sedentary people living in poorly ventilated rooms,” notes the Merck manual. “Heatstroke may develop slowly over hours to days or quickly, especially in people exerting themselves in hot, humid environments.”
Infants and children up to age four are also particularly vulnerable to heatstroke because they adjust to heat more slowly than other people, according to the Mayo Clinic.
An ounce of prevention is better than an ounce of cure, so goes a saying. “When the heat index is high, it’s best to stay in an air-conditioned environment,” says the Mayo Clinic. Now, if you must go outdoors, you can prevent heatstroke by taking these steps:
- Wear lightweight, light-colored, loose-fitting clothing and a wide-brimmed hat.
- Use a sunscreen with a sun protection factor (SPF) of 30 or more.
- Drink extra fluids. To prevent dehydration, it’s generally recommended to drink at least eight glasses of water, fruit juice, or vegetable juice per day. Because heat-related illness also can result from salt depletion, it may be advisable to substitute an electrolyte-rich sports drink for water during periods of extreme heat and humidity.
- Take additional precautions when exercising or working outdoors. The general recommendation is to drink 24 ounces of fluid two hours before exercise, and consider adding another eight ounces of water or sports drink right before exercise. During exercise, you should consume another eight ounces of water every 20 minutes, even if you don’t feel thirsty.
- Reschedule or cancel outdoor activity. If possible, shift your time outdoors to the coolest times of the day, either early morning or after sunset.
Other strategies for preventing heat stroke include:
- Monitor the color of your urine. Darker urine is a sign of dehydration. Be sure to drink enough fluids to maintain very light-colored urine.
- Measure your weight before and after physical activity. Monitoring lost water weight can help you determine how much fluid you need to drink.
- Avoid fluids containing caffeine or alcohol, because both substances can make you lose more fluids and worsen heat-related illness. Also, do not take salt tablets unless your doctor has told you to do so. The easiest and safest way to replace salt and other electrolytes during heat waves is to drink sports beverages or fruit juice.
- Check with your doctor before increasing liquid intake if you have epilepsy or heart, kidney, or liver disease; are on fluid-restricted diets; or have a problem with fluid retention.
“If you live in an apartment or house without fans or air conditioning, try to spend at least two hours each day—preferably during the hottest part of the day—in an-air-conditioned environment,” the Mayo Clinic suggests. “At home, draw your curtains, shades, or blinds during the hottest part of the day, and open windows at night on two sides of your building to create cross-ventilation.”