After a long winter, many people look forward to spending time outdoors in the summer warmth. But excess exposure to high temperatures, or performing strenuous activities during hot weather may result in life-threatening heat related illness. Just as with cold weather illness, the elderly and the very young are most at risk. But anyone can succumb to heat exposure.

Two hot weather health emergencies are heat stroke and heat exhaustion. Heat stroke occurs when the body loses its ability to regulate the internal temperature. The sweating mechanism (the body's way of cooling itself) shuts down, and the temperature rapidly rises, as high as 106ºF or greater. 

Symptoms of heat stroke include:

  • high body temperature
  • hot skin with absence of sweating
  • headache
  • dizziness
  • nausea
  • rapid pulse
  • confusion
  • loss of consciousness

Heat stroke is a medical emergency. Medical help must be sought immediately, while efforts to cool the person begin. These include moving the victim to a shady area and bringing the temperature down with cool (not cold) water applied to the body with a sponge, wet towels or sheets. Monitor the temperature until medical help arrives. If the person is nauseated or vomiting or unconscious, do not attempt to give fluids to drink.

Heat exhaustion is a milder form of heat-related illness than heat stroke. It develops more slowly, and may occur after several days of heat exposure and inadequate fluid replacement. Symptoms of heat exhaustion include:

  • profuse sweating
  • dizziness
  • weakness
  • headache
  • nausea or vomiting
  • fatigue
  • muscle cramps.

If not treated, heat exhaustion can progress to heat stroke.

If symptoms are severe or the person has a heart condition, medical attention should be summoned while cooling efforts begin. Cool the body as you would do for heat stroke, and offer cool, nonalcoholic beverages to drink. If symptoms persist longer than an hour, seek medical treatment.

Heat related illness is preventable. Here's what to do to stay safe in hot weather:

  • Listen to weather reports for heat advisories. Stay indoors, ideally in air conditioning, as much as possible when it's extremely hot outside, especially if you're older than 65.
  • Dress for the weather in lightweight, light colored, loose clothing. Try to avoid the sun, but if you'll be in the sun, cover as much skin as possible with clothing and a hat, or use an umbrella. Use sunscreen with an SPF of at least 15, and continue to apply it according to label directions.
  • Eat lighter meals; heavy meals can increase the body temperature.
  • Save strenuous outdoor activities for the cooler morning hours, if at all possible. Pace yourself, in extreme heat, by beginning the activity slowly and picking things up gradually.
  • Don't wait until you feel thirsty to drink. Increase your fluid intake, even if you're inactive.  If you're working or playing outdoors, you need to take in two to four glasses of water every hour. If you're sweating, some of this fluid can be consumed from sports beverages, which will help to replace salt and minerals lost through sweat. Those who are on fluid or salt restrictions should consult a medical professional for advice about fluid replacement and sports drinks.
  • Learn the symptoms of heat exhaustion and heat stroke. If you recognize early symptoms of heat related illness in yourself or another person, move indoors or at least to a shady area, drink cool fluids, and rest.