Extreme Heat

Conditions of extreme heat are defined as summertime temperatures that are substantially hotter and/or more humid than average for location at that time of year. Heat kills by pushing the human body beyond its limits. In extreme heat and high humidity, evaporation is slowed and the body must work extra hard to maintain a normal temperature.

Most heat disorders occur because the victim has been overexposed to heat or has over-exercised for his or her age and physical condition. Older adults, young children and those who are sick or overweight are more likely to succumb to extreme heat. Summers are often long and hot in Texas.

Take precautions to avoid heat exhaustion and heat stroke

Here are some tips:

• Keep a supply of water handy. 
• Drink plenty of water even if you do not feel thirsty.
• Limit intake of alcohol.
• Stay inside during the warmest hours and limit sun exposure.
• Protect face and skin by wearing a hat and light clothing.
• Muscle pains and spasms are the first indictor of heat exhaustion.

Heat Watch vs. Warning

Excessive Heat Warning - Take Action! An Excessive Heat Warning is issued within 12 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this Warning is when the maximum heat index temperature is expected to be 105° or higher for at least 2 days and nighttime air temperatures will not drop below 75°; however, these criteria vary across the country, especially for areas not used to extreme heat conditions. If you don't take precautions immediately when conditions are extreme, you may become seriously ill.

Excessive Heat Watches - Be Prepared! Heat watches are issued when conditions are favorable for an excessive heat event in the next 24 to 72 hours. A Watch is used when the risk of a heat wave has increased but its occurrence and timing is still uncertain.

Heat Advisory - Take Action! A Heat Advisory is issued within 12 hours of the onset of extremely dangerous heat conditions. The general rule of thumb for this Advisory is when the maximum heat index temperature is expected to be 100° or higher for at least 2 days, and nighttime air temperatures will not drop below 75°; however, these criteria vary across the country, especially for areas that are not used to dangerous heat conditions. Take precautions to avoid heat illness. If you don't take precautions, you may become seriously ill.

Heat Related Illnesses

During extremely hot and humid weather, your body's ability to cool itself is challenged. If the body cannot cool itself properly or if dehydration occurs, then body temperature can rise further which may cause a heat-related illness.