Last week I read an interesting article by Joe Palca on NPR's food blog about drinking hot drinks to cool you down on a hot day. Walking outside this morning, I couldn't help but notice that EVERYONE was carrying an iced coffee. Seems reasonable, since it is already 90 degrees at 10:00 AM, but I bet if I bumped into NPR's Joe Palca he would be caring a smoking-hot cappuccino instead.
In the article he explains, "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."
Mmmmm I'm confused Joe. Didn't you just tell me that hot coffee will make me sweat? Lovely.
"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.'"
I'm sure the science behind all this is true... but there is something refreshing about a cold iced coffee that a hot cappuccino will never be able to emulate.