Medical information  
 Terms Glossary
 First Aid
 Diet Information
 Preventive Medicine
 Immunization Schedules
 Biological Warfare Effects & Treatment
 Men's health
 Atlas of skin diseases
 Drug encyclopedia
 Atlas of human anatomy
 Alternative medicine
 Baby's developmental milestones
 Medical laboratory tests
 Smoking and health effect
 Advice for travelers
 Hearth attack: risk chart
 Diabetes: risk chart
 Cancer: risk chart
 Alcoholism and treatment
 Topic of the Week
 Medical Topic
 Latest News
 News Archive
  » First Aid  »  Overexposure
Overexposure to extremes of temperature is often a matter of carelessness or disregard of the dangers of environmental climatic extremes. The very young, the very old, the chronically ill, alcoholics, and drug abusers as well as outdoor enthusiasts are especially vulnerable to overexposure.


Frostbite occurs with prolonged exposure to subfreezing temperatures. The risk increases as the temperature declines or the wind increases.

  • Progressive, painful loss of feeling leading to numbness
  • White or blue appearance of the skin
  • Firmness of the skin to the touch
  • Loss of function
  • Do not try to rewarm the affected parts. Gently wrap the affected parts in a blanket, dry clothing, or several layers of newspaper and transport the person to a hospital as soon as possible.
  • Do not rub or massage the frostbitten area with anything, particularly not with snow as some home remedies suggest. Rubbing increases the risk of tissue damage. Snow merely adds to the danger of freezing.
  • If treatment must be undertaken outside a hospital, bring the person indoors and begin warming the frostbitten parts immediately by immersing in warm water at a temperature of about 104–108F (40–42C). Rewarming may take 45 minutes to an hour. Successful rewarming leads to progressive return of function, color, and sensations and may result in blistering, which is normal. This process may be very painful; aspirin or acetaminophen may be given. Do not break the blisters.
  • Do not expose frostbitten skin to the intense heat of a stove, radiator, open fire, or heating pad.
  • If a hot beverage such as coffee or tea is available, offer it if the person is fully awake. Do not allow the person to drink alcoholic beverages.
  • Apply dry, sterile gauze for protection.
  • During travel to the hospital or indoors avoid refreezing of the frostbitten part.
  • Treat hypothermia (see below) before treating frostbite.


Hypothermia refers to subnormal central body temperature that may be due to overexposure to cold temperatures. The very young, the old, alcohol and drug abusers, and outdoor enthusiasts are particularly vulnerable to this condition. In accidental hypothermia, the body temperature lowers progressively, and in extreme cases death from cardiac arrest may result.


Shivering, conscious and alert, but may have difficulty speaking or walking. Body temperature is 90 to 95F (32.2 to 35C). (Be aware that many household thermometers do not register temperatures below 94F [34.4C], so it may be hard to tell what the body temperature is.)


Wrap person in warm blankets or clothes and remove immediately to a warm shelter. Give warm, nonalcoholic drinks.

  • Body temperature below 90F (32.2C)
  • Person stops shivering
  • Altered mental status ranging from lethargy to unconsciousness
  • Check vital signs: Respiration and pulse may be difficult to detect. Check carefully. If they appear completely absent and you are alone, call for help and then begin CPR.
  • Take the person to a hospital emergency room immediately. When alone in an isolated area, getting the person to a medical facility is the highest priority.
  • If help or a hospital is unavailable, wrap the person in warm blankets and take to a warm shelter. Try to avoid jostling the person when transporting. This may affect heart rhythm.
  • Remove wet clothing and wrap the person in warm, dry blankets. Use hot water bottles or another person's body next to the victim to warm the victim.
  • Rewarming takes several hours, with some risk of further fall in body temperature as well as shock, so it is always preferable to take the person to a hospital when possible.



Cramps in various parts of the body or muscles during or after exercise as a result of salt (electrolyte) and water losses through sweating.

  • Replenish salt and fluids to alleviate cramps. Administer fluids. If possible, give fluids as 1/4 to 1/2 teaspoon of salt dissolved in a quart of cool fruit juice. Commercial sport drinks with a moderate amount of sugar are also acceptable.
  • Stretch cramped muscles.


  • Pale, moist skin.
  • Body temperature is normal or only moderately elevated (102F/38.9C).
  • Damp skin.
  • Nausea, weakness, light headedness, and possibly fainting without prolonged loss of consciousness.
  • Very painful cramps may follow strenuous activity.
  • Move the person to a cool, shady, or air-conditioned place and have her lie down with feet elevated.
  • Loosen or remove most clothing.
  • Apply cool, wet compresses to head and torso.
  • Administer fluids as described in the information about heat cramps in the section "Overexposure."


Heat stroke is a medical emergency that occurs most often in hot, very humid weather. This type of heat injury occurs often in healthier people such as athletes and military recruits.

  • Person feels hot to the touch and skin is red and dry.
  • Body's internal cooling mechanism has ceased to function, so sweating may have stopped and body temperature has climbed to 104F (40C) or higher.
  • Rapid heartbeat.
  • Confusion, and agitation or lethargy, stupor, and loss of consciousness.
  • Summon an ambulance and emergency medical help immediately.
  • While waiting for the ambulance, move the person indoors to an air-conditioned area or to a shady place.
  • Remove clothing, and cool by spraying the person with cool water. Fan the person to evaporate this water and increase heat loss.
  • If a thermometer is available, check the person's temperature and stop cooling measures when it comes down to 102F (38.9C).
  • Exercise commonsense precautions during hot, humid weather. Wear light clothes, drink plenty of fluids, and avoid overexposure to the sun.
  • Take a cool bath or shower once or twice daily.
  • Seek air-conditioned places for rest.
  • Avoid strenuous activity in very hot and humid weather, particularly during the hottest part of the day.
  • Use extreme caution in hot weather if you suffer a chronic disease (cardiovascular disease, neurological problems, or dermatological conditions).
  • If you regularly take medication, get your doctor's advice about hot-weather activity.