My father tortured his children with logic. Case in point: on hot summer days, when we were bordering on heatstroke, my father liked to urge us to drink something hot, rather than cold, to provide cool relief to our boiling bodies. As a child, a hot child mind you, this is not the sort of logic you really wanted to hear. Still my father contended that drinking a hot beverage would more effectively cool you down than drinking an ice-cold soda, and there is science to prove it. Needless to say we were not swayed by his insistence, nor his faith in science.
It wasn’t until years on, when I visited India, that I realized my father had the right idea. In the heat of the day, Indians would routinely “take tea” even though the ambient temperature was around 34 C. I tried it, and while it felt counterintuitive to be pouring hot liquid down your gullet when the rubber was melting on the bottom of your sneakers, it kind of worked. And beyond the folktale aspect of hot drink for a hot day, there is indeed science that backs it up. NPR recently ran a report looking into this phenomenon and, while a glass of iced tea feels a lot more natural, drinking hot tea on a hot day actually cools your body more effectively.
NPR reporter Joe Palca spoke with Peter McNaughton, a neuroscientist at the University of Cambridge on the subject. It turns out that there are nerves in our tongue and mouth wired with receptors. While there are all kinds of receptors in your mouth, your tongue has a particular receptor that is wired to respond specifically to heat. “The hot drink somehow has an effect on your systemic cooling mechanisms, which exceeds its actual effect in terms of heating your body,” says McNaughton. So in essence, drinking hot tea on a hot tea makes you temporarily hotter, but it also starts you sweating and, in a respect, over compensates for the heat by throwing your systemic cooling mechanism in full swing. Go figure?
Does anyone routinely drink hot when the thermometer is high? Does it work for you? If drinking hot when the weather is sweltering works to cool you down, does drinking hot when it is cold make you colder?