Heat Safety for Humans
From Oregon Hikers Field Guide
Contents |
Heat Illness
Signs that someone is suffering from heat exhaustion:
- Skin is cold and pale, but coloring can vary
- Sweating
- Dizziness
- Fainting
- Weakness, restlessness
- Dilated pupils
- Nausea, vomiting
- Rapid and weak pulse caused by dehydration
Victims of heat exhaustion have a great fluid and salt deficit, which must be corrected. If they are showing signs of dizziness or weakness, get them to a cooler or shaded spot and have them sit or lie down to avoid injury. Loosen clothing, elevate the feet, and apply cool, wet cloths. Monitor their temperature, give them water (sipping), or particularly fluids containing salt, until they start showing signs of improvement (restored body fluids and normal urinary output). Drugs such as aspirin should not be administered as they increase the bleeding tendency which is a common complication of heat illness. They should not resume vigorous physical activity the rest of that day, and may need to seek medical attention.
Heat Stroke
Heat stroke (also called sunstroke) is a more severe form of heat illness. The onset is typically very rapid.
Heat Stroke symptoms that require immediate attention! :
- Mental function changes: confusion, irrational behavior, lack of coordination, sometimes convulsions, unconsciousness
- Body temperature that exceeds 103° F (temperatures at this rate are considered life-threatening)
- Skin that is red, dry and hot to the touch
- Constricted pupils
- Decreased evidence of sweating
- Showing symptoms of shock brought on by low blood pressure
- Quickened pulse and respiratory rates
- Pounding headache
Move the victim to a cooler, shaded spot as rapidly as possible. Efforts to lower the body temperature should begin immediately! Suggestions: Loosen or remove clothing and fan skin to increase air circulation and evaporation. Cover extremities and trunk with cool, wet cloths. Immerse in cool (not icy) water. Ice packs tend to make the blood vessels constrict and may actually delay cooling or cause cold injuries. If they are used, wrap in towels and apply with caution to the armpit, groin, and sides of neck. Massage limbs while cooling to propel circulation. Victim may need mouth-to-mouth resuscitation or oxygen administered.
If the victim is experiencing one or more of the above symptoms, you should take them to or get medical emergency services immediately for treatment! If the victim is still conscious and showing symptoms of heat stroke, try to give them at least one cup of cold water (sipping) every 15 minutes until medical services arrive.
- Acclimatization preparation when possible.
- Limit the amount of time spent in the heat, particularly when the temperatures reach 82° F and higher. Be out at the times of day when the sun and heat are less intense.
- Use proper sunscreen (and apply an hour or so before exposure so that it can bond to the outer layer of skin, and then renew frequently. But in some cases, too much lotion may interfere with the body’s ability to cool itself by preventing perspiration from evaporating, so use good judgment.)
- Dress in lightweight and light-colored clothing .
- Keep well hydrated by taking frequent water breaks, and start drinking water before you begin your outing. (The body can lose about two quarts of water an hour on hot days.)
- Wear good sunglasses, a brimmed hat, wet and cool the head and body with water often.
- Rest in the shade, ease up on strenuous activity.
- Appetite may diminish; keep a variety of appealing foods available.
- Carry some sodium and potassium-rich snacks, drinks and meals such as dried bananas, apricots, carrots, corn, raisins, chocolate, salty nuts and seeds, crackers, peanut butter, to replace your body’s lost electrolytes (which will also help reduce muscle cramps). A recipe to make your own electrolyte mix: For each liter of water, mix ½ teaspoon salt (sodium chloride), ½ teaspoon baking soda (sodium bicarbonate), ¼ teaspoon salt substitute (potassium chloride), and sugar or honey to taste. Alternate this drink with equal amounts of plain water.
- Do not drink caffeinated beverages or alcohol as they increase water loss through urination.
- Higher risk persons: being over 50, obese, fatigued, not in condition or acclimatized to heat, recent illness, cardiovascular conditions, diabetes, use of antihistamines, amphetamines, or any dehydrating drugs.
Even if acclimatized to the heat, one needs to know and recognize the hazards, and the symptons of heat illness. With knowledge, preparation, fluid replacement and appropriate care, heat casualties in warm weather activities can be avoided. Be smart and careful out there!
Resources
- Medicine for Mountaineering (3rd Edition) edited by James A. Wilkerson M.D.
- A Hikers Companion (12,000 Miles of Trail-Tested Wisdom) by Cindy Ross and Todd Gladfelter
- Wilderness Emergency Care (training manual) by Steve Donlan