Have the person lie down in a cool place. Raise the person's feet about 12 inches.
Apply cool, wet cloths (or cool water directly) to the person's skin and use a fan to lower body temperature. Place cold compresses on the person's neck, groin, and armpits.
If alert, give the person beverages to sip (such as Gatorade), or make a salted drink by adding a teaspoon of salt per quart of water. Give a half cup every 15 minutes. Cool water will do if salt beverages are not available.
For muscle cramps, give beverages as above and massage affected muscles gently, but firmly, until they relax.
John E. Duldner, Jr., MD, MS, Assistant Professor of Emergency Medicine Director of Research, Department of Emergency Medicine Akron General Medical Center and Northeastern Ohio Universities College of Medicine. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
References
Jardine DS.Heat illness and heat stroke. Pediatr Rev. 2007 Jul;28(7):249-58.