Dr. Doug Graham, an athlete, raw food expert, and author of The 80/10/10 Diet says it’s not 100% clear cut. “Well, it does and it doesn’t. By ingesting a hot liquid, you introduce heat to the body, and raise the body temperature. The body must cool itself to bring body temp down to normal. So, cooling responses are generated by drinking hot tea. But those cooling responses are to neutralize the heat of the liquid and the fact that the body temp has been abnormally raised–not really cool the body.”
So you might feel the cooling effect of perspiration after you drink hot tea or coffee, but your body is really just trying to maintain a stable temperature.
Dr. Bess Stillman, an Integrative Medicine consultant and Emergency Physician, agrees. She explains in detail the chemical reactions that happen in your body when you drink a hot tea in the summer that make it seem like a great short-term solution to uncomfortably hot summer weather. The tongue contains receptors that respond to heat. If you eat something hot, the receptors are thought to signal the brain that they’re warming up. When the hot drink reaches your belly, it also signals your brain that your core temperature is higher than that of your surroundings. In response, the hypothalamus – the part of the brain responsible for controlling your temperature—turns on cooling mechanisms, so you sweat. When sweat evaporates, you feel cooler. But in the long-term, she says, it can actually lead to dehydration and hurt your body’s ability to regulate its core temperature.
Most non-herbal tea also contains caffeine, which is a diuretic—meaning it causes your kidneys to dump water from your body into your urine. Dehydration is one of the leading risks for hyperthermia in the summer seasons. Therefore, in the long run hot tea may increase your core temperature and dehydrate you, leading to heat related illness, which people of all ages and health are at risk for.
If you’re desperate to cool off, we recommend drinking something cold to avoid the possibility of hyperthermia, or placing ice packs on pulse points (like under the armpits). Don’t forget, the liquid you drink isn’t smart enough to be able to tell what the season is!!