News

Nov 10, 2023

Wearing sweats in August heat is ill

As a physician, I have to respond to a potentially dangerous misconception contained in the Associated Press article about NFL teams trying to adapt to oppressive heat conditions during their

As a physician, I have to respond to a potentially dangerous misconception contained in the Associated Press article about NFL teams trying to adapt to oppressive heat conditions during their preseason training sessions (“Trying to beat the heat,” July 30). The article stated “some players wear hoodies and sweatpants so they can sweat ‘and let that heat leave your body. If you don’t, you can potentially be putting yourself at risk.’”

Wearing such clothing while exercising in the heat will actually increase the risk of heat-related illness, such as heat exhaustion or heat stroke. The thickness of sweat clothes acts as insulation keeping heat from leaving the body and increasing the body temperature. Sweating will be increased, but this only increases the risk of dehydration from fluid, not heat, leaving the body. Sweat can potentially cool the body through evaporation, but trapping sweat in the absorbent material of sweat clothes will prevent evaporation and cooling, further increasing the risk of raising the body’s core temperature. Wearing dark-colored clothing will also increase the absorption of heat from solar radiation and most colored clothing will become several shades darker when saturated with sweat.

It is recommended to wear lightweight, light-colored clothing when exercising in hot weather and to hydrate before, during and after any such exercise. Heat-retaining helmets and pads should be limited until athletes have acclimated to hot-weather exercise. When the heat index is elevated from high humidity, sweating becomes even less efficient at cooling the body because the sweat can’t evaporate as readily and increased caution is needed on these hot and humid days. These precautions also apply to people working outdoors on days with high heat and humidity.

With high school athletes soon starting their preseason training activities, it is important to keep them as safe as possible as they prepare for their fall sports. Avoiding potentially dangerous training methods such as wearing sweat clothes in extreme heat and humidity will help reduce the risk of heat-related illness. Frequent fluid breaks and rest breaks in shady areas will help to prevent dehydration and promote cooling.

July was the hottest month on record with a number of days with record-setting heat. Taking appropriate precautions to promote hydration and cooling when exercising in such conditions becomes increasingly important, but also increasingly difficult. In the bigger, global picture, taking the difficult steps to slow the warming of our planet will also be necessary to allow for safe exercise during increasingly warm summers.

— Michael Ichniowski, Lutherville

Add your voice: Respond to this piece or other Sun content by submitting your own letter.