Aug 5 2009
The first sign of dangerous heat stroke can be just that – no sweat. As the temperature rises, your body’s natural cooling mechanism, sweat (or more kindly, perspiration), evaporates and helps to cool your body. But on those hot, humid cut-the-air-with-a knife days, evaporation is slowed and your body may not be able to keep itself cool.
"The best defense against any heat-related illness is prevention. Be extra careful when the heat index is 90 degrees or above. (The heat index tells you how hot it feels in the shade when relative humidity combines with the air temperature.) Always, always drink plenty of water when the heat index is high and avoid caffeine and alcohol. If you must be outdoors, take frequent breaks inside or in the shade,” says Marilyn J. Heine, M.D., a Bucks County emergency physician and member of the Pennsylvania Medical Society.
"If you take precautions and know the warning signs, you generally can prevent heat stoke. Keep a close watch on the elderly and infants, people on certain medications, athletes and outdoor workers.”
Recognize these warning signs:
- Pale skin
- Fatigue, weakness
- Dizzy or nauseous
- Sweating profusely
- Rapid pulse
- Fast, shallow breathing
- Muscle weakness or cramps
Dr. Heine explains, “If you experience any of these symptoms, get out of the heat quickly and rest in a cool, shady place. Drink plenty of water or other fluids containing sugar and salt. Do NOT drink alcohol; that can make it worse. If you don’t feel better within 30 minutes, contact your doctor. If heat exhaustion isn’t treated, it can progress to heat stroke.”
Seek treatment immediately if any of these warning signs are present:
- Skin that feels hot and dry, but not sweaty
- Confusion or loss of consciousness
- Throbbing headache
- Frequent vomiting
- Shortness of breath or trouble breathing
Heat stroke is much more serious than heat exhaustion -- it can kill you. People with heat stroke may have seizures or go into a coma and most also have a fever.
"If you suspect heat stroke, call 911 immediately," Dr. Heine says, "Move the victim to a cooler location, remove heavy clothing, fan the body and wet it down with a cool sponge or cloth, and encourage the individual to drink cool fluids." At the hospital, the patient probably will be given fluids intravenously.
The key to beating the heat, of course, is prevention. Dr. Heine offers the following tips for keeping cool and healthy despite the sweltering sun and humidity.
- Don't overexert yourself.
- Drink a quart of fluids an hour.
- Wear loose clothing light in color and fabric, as well as a hat and sunblock, and stay in the shade or indoors if possible.
- Open windows and use fans, or turn on air conditioning. If you don't have air conditioning, go to a public place that does, like a mall, library, or movie theater.
- Avoid caffeine and alcohol, which can speed up dehydration.
- Finally, be a good neighbor - check on the elderly and chronically ill persons regularly to make sure they're bearing up under the heat.
Having heat exhaustion or heat stroke makes you more sensitive to hot conditions for about a week afterwards. Be especially careful not to exercise too hard, and avoid hot weather. Ask your doctor to tell you when it is safe to return to your normal activities.
According to Dr. Heine, there are two types of heat stroke, and everyone is susceptible, athletes and couch potatoes alike. Classic or non-exercise-induced heat stroke affects those exposed to extremely hot environments for an intolerable length of time.
Infants and young children
Babies and young children don’t have the ability to hydrate themselves or know when to get out of the heat.
- Never leave a child in a closed, parked vehicle, not even for a minute. The temperature inside a parked car can soar into triple digits within minutes. We’ve all heard the horror stories. Don’t do it.
- Make sure babies and children drink plenty of fluids. If you are thirsty, chances are your little ones could also use a beverage. Avoid beverages with caffeine, or a large amount of sugar.
- Avoid bundling infants in heavy blankets or clothing. Like adults, babies need to air out in order to cool down.
- During the hottest hours of the day, keep children indoors in an air-conditioned environment as much as possible. Families without air conditioning should pull shades over the windows and use room fans.
The elderly or infirm
The elderly are more prone to heat-related illness for several reasons:
- Their bodies do not adjust well to sudden changes in temperature.
- They are more likely to have a chronic medical condition that upsets normal body responses to heat.
- They are more likely to take prescription medicines that impair the body's ability to regulate its temperature or that inhibit perspiration.
Dr. Heine recalls a 78-year-old woman who was transported by ambulance to the emergency department after a neighbor noticed she hadn't been out of her apartment for two days. The temperature had surpassed 90 degrees and the humidity was stifling. The woman was dehydrated, with a temperature of 104.7 degrees and a decreased blood pressure of 100/70. She was treated with intravenous fluids and then hospitalized.
You can help:
- Visit older adults at risk at least twice a day and watch for signs of heat exhaustion or heat stroke.
- Take them to air-conditioned locations if they have transportation problems.
- Make sure older adults have an electric fan and can take a cool shower or bath.
People taking certain medications
Many medications also can put you in danger of heat stroke:
- Allergy medicines
- Cough and cold medicines
- Some blood pressure and heart medicines
- Diet pills (amphetamines)
- Irritable bladder and irritable bowel medicines
- Some mental health medicines
- Seizure medicines
- Thyroid pills
- Water pills
Talk to your doctor about what medicines you are taking. He or she can tell you if your medicine puts you at risk for heat stroke.
The other type of heat stroke - exertional or activity-induced - primarily affects athletes, laborers, and soldiers - persons who overdo physical activity in very hot temperatures.
While football players who wear body-covering uniforms/equipment and practice in the hottest temperatures are especially prone to dehydration and heat stroke, all athletes are at risk in very high temperatures. Young athletes, in particular, are at higher risk for developing heat-related illness than adults because they absorb heat faster than adults, don't sweat as much and often don't "want" to drink fluids during exercise.
Do your best to avoid heat illness by following these tips from the American Medical Society for Sports Medicine :
- Alert your coach or athletic trainer anytime you don’t feel well.
- Allow for acclimatization (adaptation) to hot, humid conditions. Gradually increase workout intensity and duration over a 10 to 14 day period. This helps train your body to drink more, increase blood volume and sweat better.
- Wear loose-fitting, light-colored clothing to help promote heat loss.
- Save strenuous exercise for early morning or late evening, not during the heat of the day. If this can’t be avoided, modify workout intensity and increase the number and length of rest breaks.
- When exercising outside, stay in the shade as much as possible.
- Drink up when it’s hot and when it’s not! You should have unlimited access to fluids throughout practices or competition.
- Monitor your hydration status. Ideally, body weight should be taken before and after practice to determine sweat loss. Check that urine color is pale like lemonade, not concentrated like apple juice.
- Two hours before exercise, drink at least 16 oz (2 cups) fluid.
- During exercise, drink at least 7–10 oz (about one cup) every 10–20 minutes.
- After a workout or competition, drink 24 oz (3 cups) per pound of body weight lost through sweat.
Working in the heat
Firefighters, contractors, miners, farmers, laborers, to name a few, are highly susceptible to heat-related illness when the temperature climbs. If you work in hot environment, whether indoors or out, the key to avoiding heat-related illness is to follow the general guidelines – gradually build up your tolerance to heat over 5-7 days, hydrate, take breaks in the shade or air-conditioning, use fans when possible, avoid exertion during the hottest parts of the day, pace yourself and know the signs of heat-related illness.
Drinking enough water is critical. In the course of a day's work in the heat, you may produce as much as 2 to 3 gallons of sweat. To avoid dehydration, make sure your water intake during the workday is about equal to the amount of sweat produced. Most workers exposed to hot conditions drink less fluids than needed because they’re just not thirsty. Do your best to drink 5 to 7 ounces of fluids every 15 to 20 minutes to replenish the necessary fluids in your body.
For more information, visit the Pennsylvania Medical Society’s Family Health and Wellness website at www.myfamilywellness.org.