Heat-Related Illnesses
Prevention
The following tips may help prevent a heat-related illness. Be aware of the symptoms of heat-related illnesses and the warning signs of dehydration.
- Practise heat safety measures when you are physically active in hot weather. This is especially important for outdoor workers and military personnel. Avoid strenuous activity in hot, humid weather or during the hottest part of the day (between 10 a.m. and 4 p.m.). Use caution during your physical activity in the heat if you have health risks.
- Increase your fluid intake when exercising or working outside during hot weather. Drink plenty of rehydration drinks, juices, or water to replace fluids, especially if you sweat a lot. Drinks, such as sports drinks, that have electrolytes work best.
- Drink on schedule. Two hours before exercising, drink 700 mL (24 fl oz) of fluid. Drink 475 mL (16 fl oz) of fluid 15 minutes before exercising. Continue drinking 240 mL (8 fl oz) of fluid every 15 minutes while exercising.
- Drink rehydration drinks or sports drinks, such as Gatorade or All sport thirst quenchers, which are absorbed quickly as water but also replace sugar, sodium, and other nutrients. Eat fruits and vegetables to replace nutrients.
- Check your urine. Urine should be clear to pale yellow, and there should be a large amount if you are drinking adequately. You should urinate every 2 to 4 hours during an activity when you are staying properly hydrated. If your urine output decreases, drink more fluids.
- Do not spend much time in the sun. If possible, exercise or work outside during the cooler times of the day. Wear lightweight, light-coloured, loose-fitting clothing in hot weather, so your skin can cool through evaporation. Wear a wide-brimmed hat or use an umbrella for shade.
- Stay cool as much as possible. Take frequent breaks in the shade, by a fan, or in air-conditioning. Cool your skin by spraying water over your body. Take a cool bath or shower 1 to 2 times a day in hot weather.
- If you have to stand for any length of time in a hot environment, flex your leg muscles often while standing. This prevents blood from pooling in your lower legs, which can lead to fainting. Wear support hose to stimulate circulation while standing for long periods of time to prevent swelling (heat edema).
- Do not drink caffeine or alcohol. They increase blood flow to the skin and increase your risk of dehydration.
Staying physically fit can help you acclimate a hot environment. Before you travel to or work in a hotter environment, use gradual physical conditioning. This takes about 8 to 14 days for adults. Children require 10 to 14 days for their bodies to acclimate to the heat. If you travel to a hot environment and are not accustomed to the heat, cut your usual outside physical activities in half for the first 4 to 5 days. Gradually increase your activities once your body adjusts to the heat and level of activity.
Be aware that when the outdoor humidity is greater than 75%, the body's ability to lose heat by sweating is decreased . Other ways of keeping cool need to be used. The National Weather Service lists a heat index each day in the newspaper to alert people of the risk for a heat-related illness in relation to the air temperature and humidity of that day. Direct exposure to the sun can increase the risk of a heat-related illness on days when the heat index is high.
People who have had heatstroke in the past may be more sensitive to the effects of heat in the first few months following the illness, but they do not have long-term problems.
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| Author: | Jan Nissl, RN, BS | Last Updated: January 31, 2007 |
| Medical Review: | Martin Gabica, MD - Family Medicine Anne C. Poinier, MD - Internal Medicine H. Michael O'Connor, MD - Emergency Medicine | |
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| Topic Contents | |
| Topic Overview | |
| Emergencies | |
| Check Your Symptoms | |
| Home Treatment | |
 | Prevention |
| Preparing For Your Appointment | |
| Related Information | |
| Credits | |