Heat Stroke versus Heat Exhaustion

posted May 26, 2010 11:47 AM by Bryan Kolozsi

Exposure to high temperatures may lead either to excessive fluid loss and heat exhaustion or to failure of heat loss mechanisms and dangerous heat stroke.

Age, obesity, chronic alcoholism, and many drugs (over-the-counter, prescription and illegal) increase the susceptibility of heat illness, particularly heat stroke.  Though heat stroke and heat exhaustion stem from the same cause they are sharply different.

Heat Stroke

  • Cause: Inadequacy or failure of your body to lose heat (sweat).
  • Warnings: Headache, weakness, sudden loss of consciousness.
  • Appearance & signs: Hot, red, dry skin; little sweating; hard rapid pulse; very high temperature.
  • Management: Emergency cooling by wrapping or immersing in cold water or ice, immediate hospitalization.

Heat Exhaustion

  • Cause: Excessive fluid loss leading to shock.
  • Warnings: Gradual weakness, nausea, anxiety, excessive sweating and fainting.
  • Appearance & signs: Pale, grayish clammy skin, weak, slow pulse, low blood pressure and faintness.
  • Management: Fainting- head down, replace lost salt and water.

Common sense is the best prevention; strenuous exertion in a very hot environment, inadequately ventilated space or heavy clothes should be avoided.  High humidity does not allow the body to cool by its normal sweating mechanism, and hot dry heat creates dehydration imperceptibly.

By the time you are thirsty you are already drink water often when exercising, gardening, and playing.  8 glasses is the easiest number to remember but a more accurate amount for your body is to multiply your body weight in pounds by 0.5 and 0.7 - the numbers generated are the range, in ounces, of water you should drink each day.  With strenuous exercise water and drinks with electrolytes are beneficial to the muscle recovery.

135 x 0.5 = 67.5

135 x 0.7 = 94.5

A cup is 8 oz so I would really need to drink between 9-11 cups of water a day normally and more with any of the conditions stated.