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Thu 12 Jul, 2012 10:03 am
Cool Down With A Hot Drink? It's Not As Crazy As You Think
July 11, 2012
by Joe Palca - NPR Morning Edition
Hot tea on a hot day? Not for me, thank you. Not my idea of how to cool down.
But I've been doing a series of stories for Morning Edition called Summer Science, where I tackle such subjects as how to roast the perfect marshmallow and what causes that sharp headache some people get when they eat ice cream. For my next installment, Morning Edition Executive Producer Madhulika Sikka asked me to explain why drinking hot tea cools you off on a hot day.
It does?
"Trust me," she said. "I'm Indian, I'm British. A billion Indians can't be wrong. They drink hot tea in hot weather."
So I started to make some calls.
Palca and Morning Edition Executive Producer Madhulika Sikka test if hot tea can cool you down on a hot day.
Most scientists I asked for comment demurred, but Peter McNaughton, a neuroscientist at the University of Cambridge, offered an answer.
McNaughton agrees the whole thing is counterintuitive. "Obviously a hot drink makes you hotter and a cold drink makes you colder. So why would you want to get hotter on a hot day?" he asked rhetorically.
Here's how he explains why you might want to do that. Turns out there are nerves in our tongue and mouth that have special molecules in them called receptors. As the name suggests, these receptors receive signals from the world outside the nerve.
There are all sorts of receptors in all sorts of nerves, but the nerves in the tongue have a lot of one particular receptor that responds to heat. It's called the TRPV1 receptor, if anyone wants to know.
So when you eat or drink something hot, these receptors get that heat signal, and that tells the nerve to let the brain know what's going on.
When the brain gets the message "It's hot in here," it turns on the mechanism we have to cool ourselves off: sweating.
Yes, the hot drink makes you hotter ... but it does something else, too.
"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.
One other interesting thing. These TRPV1 receptors respond to hot heat, but they also respond to chemicals in chili peppers, which is why chili peppers seem hot. "That's probably why chili peppers are so popular in hot countries because they cause sweating and activate a whole raft of mechanisms which lower the temperature," he says.
I have to say I'm still a little skeptical about hot tea on a hot day. I'd still rather have a tall glass of ice water. What about you?
@BumbleBeeBoogie,
I long ago found that hot coffee on a hot day is much better than the iced coffee. Iced will give me a quick moment of relief and soon after I feel off again.
My first introduction to this sorbet was from my sister who would visit the zoo in the dead of winter and buy ice cream which she would then eat outside of one of the many buildings where the animals were sheltered against the elements. It seemed peculiar at the time; then one day I tried it and oddly didn't feel quite as cold. When summer rolled in...which it seems to do annually, I tried a test. Cold ice cream, cold soda, cold water, juices, various cold products and they all did the same thing. A splurge of relief followed by feeling drained even more than I had prior. I sat and ate a bowl of chili (I like the green) and drank my hot coffee and began to feel better. The better feeling stayed with me a number of hours.
@Sturgis,
I still have a cuppa most mornings in the summer.
whatever time morning happens to be...
@Sturgis,
I will have to advise Butrflynet to try your idea.
BBB
@Sturgis,
All cold coffee seems to do for me is stimulation of the gag reflex.
@BumbleBeeBoogie,
BumbleBeeBoogie wrote:Cool Down With A Hot Drink? It's Not As Crazy As You Think
I don't think it's crazy at all. And, in spite of the gee-whiz tone of the NPR report, there is nothing new at all about this. I remember as a teenager my father advising me to drink hot drinks on hot days. His understanding of the reasoning was that an intake of hot coffee or tea would equalize the temp. in your body and adjust it to the extreme heat outside. Not far from what the scientists are saying now. I drink hot coffee daily; makes absolutely no difference what the thermometer says. Always have, prob'ly always will.
@Lustig Andrei,
I used to listen to NPR often, usually on the car radio. That was a while ago.
I click on, sometimes, Bubblebee boogie's links - which are usually to NPR - and I see pabalum. They write alike.
Obviously I could follow NPR on my own sans prompts.
I may or may not agree on the politics, but I think of NPR as a sleep zone.
@ossobuco,
It's where I get my news mostly, Osso. ' Morning Edition' in the morning, 'All Things Considered' late afternoon, updates throughout the day while listening to music.
@Lustig Andrei,
I am an Indian. I drink hot tea all the time. Even when it is hot outside. It works!
@Lustig Andrei,
I did too.
Recently I see, via BBB and her many posts, transcripts, just about all seeming lame as text.
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