Heat can make us tired, but the combination of heat and humidity makes us tired. What can we do?
It’s not just a feeling: the combination of “heat and humidity” is actually harder on our bodies.
Humidity indicates how much water vapor is in the air. The warmer the weather, the more moisture the air can hold, says Jessica Lee, public program coordinator for the US National Weather Service. This is also why a very hot summer day can feel more “stuck” than a foggy spring morning.
High humidity can also prevent our body temperature from dropping, making heatstroke more dangerous. But experts say there are ways to stay safe and healthy.
Because the humidity is terrible
It has to do with our body’s cooling mechanism: sweat.
Penn Medicine professor of emergency medicine Dr. Anthony Mazzeo says that when our body overheats, it sends a mixture of water and salt to the surface of our skin, which comes out of our pores as sweat. But it is not sweat that cools us. It’s the exhaust.
Weill Cornell Medicine and New York-Presbyterian Hospital head of emergency medicine Dr. “When sweat evaporates, it takes away heat from the body,” said Rahul Sharma. A liquid requires energy to evaporate. When sweat evaporates from our skin, it takes this energy from body heat, cooling us down.
Dr. Mazzeo says the problem with high humidity is that the air is already saturated — or nearly so — with moisture. This prevents efficient evaporation of sweat. When sweat cannot evaporate, our body cannot cool down. When he can’t cool down, he sweats even more.
Associate Professor of Clinical Medicine at the University of Miami Miller School of Medicine Dr. If sweat can’t evaporate effectively, our bodies have to work harder to stay cool, says Gauri Agarwal. This can lead to exhaustion and weakness.
And the more you sweat, the more dehydrated you become, which increases the fatigue you feel, he explains.
Dr. Sharma adds that high humidity can also cause bronchoconstriction, meaning your airways narrow. This is dangerous for people with asthma or chronic obstructive pulmonary disease.
Humid air also traps allergens and pollutants, and mold grows more easily in humid conditions. All this can make breathing difficult.
How to stay safe
Hot and humid weather can be miserable, but we can take precautions:
Hydration. If the weather is forecast to be wet, drink water before you feel thirsty. This will help you avoid dehydration due to excessive sweating. Sports drinks, juices, and foods with a high water content can also keep you hydrated. But if you can, avoid alcohol, which is more dehydrating.
Reprogramming. Vigorous activity can cause your body to overheat. If you plan to go for a walk, ride a long bike, or do some other strenuous exercise, you may have to postpone it. You can also schedule your workout early in the morning or late in the evening when the temperature is lower.
Find shade. The heat is stronger in the sun, so try to avoid direct sunlight.
Dress appropriately with light clothing and breathable fabrics.