May 9, 2000

The Houston Department of Health and Human Services (HDHHS) urges the public to begin preparing for high summertime temperatures. High heat and humidity can cause moderate to severe health problems for the elderly, the very young and people with heart and respiratory problems. During the summer of 1999, 20 Harris County residents died of heat related illness, in 1998, 23 Harris County residents died from the heat.

Heat related health problems occur when the body is not able to maintain an internal temperature around 98.6 degrees. Evaporative cooling through perspiration and cooling which takes place in the lungs is normally adequate to maintain the internal body temperature. High humidity, however, reduces or eliminates the cooling effect of perspiration and respiration.

The public should avoid the use of fans without refrigerated air during excessive heat since the movement of hot humid air will accelerate the body heating and raise the internal body temperature. (Excessive heat advisories are issued by the National Weather Service.) High risk populations should seek air conditioned accommodations during the heat of the day to reduce the risk of heat related illness.

Heat related illness may begin with heat exhaustion which is characterized by fever, headache, nausea and weakness. Heat exhaustion should be treated with shade and cool water. If the body is not cooled at this point, heat stroke may follow. Heat stroke causes blood clots and heart failure. Without proper treatment, heat stroke is fatal 80 percent of the time.

To avoid the ill effects of high heat, increase water consumption well before the onset of thirst. Alcoholic beverages are discouraged in high heat conditions because they cause dehydration. Fruit juices are a good substitute for water, and if exercising, sports drinks are encouraged.

To avoid heat related illness:

• Increase water consumption.
• Conduct outdoor work or exercise in the early morning or evening when it is cooler.
• Wear light-colored, loose fitting clothing that permits the evaporation of perspiration.
• Stay out of direct sunlight; seek shade when available.
• A wide brimmed hat helps prevent sunburn as well as heat related illness.
• If the house is not air-conditioned, seek accommodations in air-conditioned facilities during
• the heat of the day: malls, movie theaters, libraries, multi-service centers, etc.
• Take frequent cool baths or showers.
• Never leave a person or a pet inside a closed car with no ventilation.