Heat illness describes health problems caused by prolonged exposure to high temperatures. Symptoms range from mild discomfort to life-threatening emergencies.
Your body normally cools itself through sweating, but extreme heat overwhelms this system. When core temperature rises above 104°F (40°C), organs begin suffering damage. Dehydration compounds the problem by reducing blood volume and impairing circulation.
| Condition | Mild Symptoms | Severe Symptoms |
|---|---|---|
| Heat rash | Red clusters of small blisters | Infection if scratched |
| Heat cramps | Muscle spasms in legs/abdomen | Nausea, heavy sweating |
| Heat exhaustion | Headache, dizziness, nausea | Confusion, fainting, rapid pulse |
| Heatstroke | - | High fever, seizures, unconsciousness |
Many people believe heat illness only affects outdoor workers or athletes. In reality, anyone can suffer - even those indoors with poor ventilation. Air conditioning provides protection but doesn't eliminate risk entirely.
A common mistake is assuming thirst indicates dehydration. By the time you feel thirsty, you've already lost 1-2% of your body weight in fluids. The CDC recommends drinking water before feeling thirsty during hot weather.
Call 911 immediately if someone shows signs of heatstroke: confusion, loss of consciousness, or body temperature above 104°F. While waiting for help, move the person to shade, remove excess clothing, and apply cool (not ice-cold) water to skin.
I once helped a marathon runner showing heat exhaustion symptoms. We moved him to shade, removed his outer gear, and had him sip water slowly. His condition improved within 15 minutes, but he required medical evaluation afterward.
Stay hydrated by drinking water regularly throughout the day. Wear light-colored, loose-fitting clothing that allows sweat evaporation. Schedule strenuous activities for cooler parts of the day.