Summer is the perfect time for yard work and exercise, but without proper precautions, heat and dehydration can make you very sick. Heat illnesses run the gamut from mild dehydration to life-threatening heat stroke. Hydration to maintain electrolyte balance is the primary way to protect yourself against heat-related illness. For most people, water is adequate. Athletes and laborers who work in hot environments may need carbohydrate-based electrolyte drinks, however.
Human cells are dependent on water for life. The outside and inside environments of each cell are aqueous, but fluids have to be balanced. When minerals and salts dissociate in water, electrolytes -- positively and negatively charged ions -- form. Water molecules are attracted to the electrolyte charge and follow the ions in and out of cells. The cell membrane is selectively permeable to electrolytes to maintain a fluid balance. When you lose a large volume of liquid in a short period of time through vomiting, sweating, diarrhea, burns or other injuries, your electrolytes become imbalanced.
An electrolyte imbalance caused by excessive sweating may give you heat cramps, according to Carnegie Mellon University. Heat cramps are painful muscle contractions which are involuntary and often prolonged. The abdominal, back, arm and calf muscles are most commonly affected, although any muscle group used for work or exercise may go into spasm. The cramps can be caused by too much or too little salt. In either case, muscle spasms should be treated with hydration in 15- to 20-minute intervals.
If you don't cool down and hydrate, heat cramps may progress to heat exhaustion, which is characterized by dizziness, vertigo, thirst, weakness, nausea and giddiness. If your body temperature continues to rise and you fail to hydrate, you run the risk of heat stroke -- the most serious of heat-related illnesses. Heat stroke, which is a medical emergency, occurs when your body's temperature regulation systems fail and your body temperature exceeds 104 degrees Fahrenheit. Intravenous fluids administered at the hospital are necessary to restore fluid and electrolyte balance and prevent damage to the kidneys, brain, heart and muscles. Left untreated, heat stroke can end in death.
Regular hydration is the best preventative measure against heat illness. If you're working or exercising in a hot environment, drink 1 cup of cool water every 20 minutes, recommends Carnegie Mellon University. Carbohydrate-based electrolyte drinks are also a good option, but be wary of beverages with a high sugar content. Work during the cooler part of the day and be on the lookout for signs of heat illness in yourself and others. If you feel unwell, retreat to an air-conditioned area to rehydrate.