Extreme Heat and Health

Summer in Greater Houston routinely produces heat that is dangerous to anyone who underestimates it. The combination of high air temperatures and high humidity along the Gulf Coast pushes the heat index — the temperature the body actually experiences — well above the air temperature, often into the triple digits for days at a time. Recent summers have set records for the number of consecutive days above 100 degrees at George Bush Intercontinental and Hobby airports.

Heat Index and Warnings

The National Weather Service issues a heat advisory when the heat index is forecast to reach roughly 108 degrees, and an excessive heat warning when it reaches roughly 113 degrees, with thresholds varying by season. These thresholds are not arbitrary; they reflect the point at which emergency-room visits and outdoor-work fatalities climb sharply in Houston data.

Vulnerable Populations

Heat illness is not distributed evenly. The most vulnerable Houstonians are older adults, infants, people with chronic cardiovascular or respiratory conditions, people taking certain medications, outdoor workers, athletes, and people without reliable air conditioning. Check on elderly neighbors and relatives during heat waves, especially those who live alone.

Cooling Centers

The City of Houston and Harris County open public cooling centers during prolonged heat events; locations are announced through ReadyHarris.org and local news outlets. Public libraries, recreation centers, and many faith-based organizations also open as informal cooling spaces.

Recognizing Heat Illness

Heat exhaustion presents as heavy sweating, weakness, clammy skin, nausea, and headache. Move the person to a cool space, loosen clothing, and provide cool water. Heat stroke is a medical emergency: body temperature above 103 degrees, hot dry skin, confusion, and possible loss of consciousness. Call 911 immediately and begin cooling the person with water or ice packs while you wait.

Hydration and Outdoor Work

Drink water regularly throughout the day, not only when you feel thirsty. Workers outdoors should schedule strenuous tasks for early morning when possible, take frequent breaks in shade, and watch coworkers for early signs of heat illness. Athletic events, construction sites, and outdoor maintenance crews should adjust schedules during heat advisories.

Related: supplies, road conditions.