How Humidity Increases Risk of Heat Stroke
When it’s billions of degrees with high humidity, the heat can feel like a heavy blanket suffocating you. As it turns out, the combination of heat and humidity can also increase the risk of heat stroke.
How is dry heat different from wet heat?
When it comes to dry and wet heat, the main difference is that humidity prevents sweat from evaporating from the surface of your skin, which helps your body cool down.
“When it’s much drier, it’s much easier for any sweat to leave your body quickly,” said Neil Gandy, an emergency physician at Houston Methodist Hospital , where the heat and humidity are extreme. “The extra moisture keeps you from sweating effectively.”
When sweat sticks to your skin instead of evaporating, you get hotter than you really are. The combination of ambient temperature and humidity is what goes into the heat index , which is what the temperature is like. The higher the combination of heat and humidity, the higher the heat index.
How to avoid heat stroke
Gandhi usually sees a spike in heatstroke cases in early summer when people are just getting used to warmer temperatures, during heat waves when the heat index can be especially high, or at the start of the school year when football practice kicks off.
When it comes to preventing heat stroke, one important practice is heat acclimatization , which allows your body to gradually get used to warmer temperatures. Giving your body time to adjust over days or weeks can cause physiological adaptations to heat, such as increased sweating efficiency, increased blood flow to the skin, and the ability to move around at a lower heart rate and body temperature. “Your body is an amazing machine,” Gandhi said. “The more time to acclimatize, the better.”
Of course, other ways to avoid heat stroke include limiting your exposure to extreme heat, such as staying indoors during the hottest part of the day and staying hydrated. Plain water is great for hydration, although if you find that drinking liquids with salts makes you feel better, “you should definitely keep doing this,” Gandhi said. “If we look at the evidence, salts are not harmful, which means that a small amount of salt will not harm people. But on a physiological level, water is as effective as any sports drink.”
Know the warning signs of heat stroke
Warning signs of heat stroke may include confusion, loss of consciousness, vomiting, hot, dry skin, profuse sweating, and very high body temperature. If you start noticing these signs in yourself or others, then you need to seek help immediately. Take special care of young children and the elderly, as they are particularly susceptible to heatstroke.
“This is a real medical emergency,” Gandhi said. “This person should go to the emergency room immediately. Otherwise, the damage may be irreversible.” However, with early detection and proper treatment, “most patients recover fairly well,” he said.