Stuart Ritchie reminds us that hot beverages don't actually cool us down. The short version is there was one study in Canada of semi-nude participants sweating more during exercise because of the higher internal temperature. Just a little bit. In highly limited circumstances.
Nine “semi-nude” men cycled non-strenuously on a stationary bike for 75 minutes in a warm-ish room (24°C), and had their temperatures measured in their oesophagus (via a probe in their nose) and rectally. They were linked up to a calorimeter, which calculated their heat production from the amount of oxygen they were using and the carbon dioxide they were breathing out. They were also weighed with a very sensitive scale to measure sweat loss.
Just before, and then a few times during, the exercise they were given a controlled amount of water, adding up to just under a litre across the whole experiment, at various temperatures: 1.5°C, 10°C, 37°C, and 50°C. Each participant did four sessions, one at each of the water temperatures.
To note a few things already: n = 9; only males; doing exercise for quite a long time; in a not-particularly-hot room; rapidly drinking water, not sipping a cup of tea. They also had a big fan pointed at them to help their sweat to evaporate away. These are just a few of the differences between this experiment and perhaps the average person’s situation in a heatwave - and I haven’t even mentioned the fact they were doing all this while they had a thermometer “inserted to a minimum of 12 cm past [their] anal sphincter”.
That's it. It was in Smithsonian, so it got wide play, but that's the extent of the research.
4 comments:
1.5°C, 10°C, 37°C, and 50°C
OR
cold - right out of the fridge
tepid - or slightly cooler
lukewarm - ie, 98.6
warm - 122 degrees fahrenheit or about 15 degrees lower than coffee is generally served
...in a 75 degree room with a fan. The results would probably have been similar if the water was poured over the participants' heads.
To paraphrase James Carville: It's the fan, stupid!
Yeah, pretty much. Drink hot coffee or tea because you like it, not because of any theory it will cool you off.
I'd never before heard that hot beverages were supposed to cool you off. It sounds odd--as though coffee was supposed to mung up your thermal regulation. But that's governed by the skin and the brain, and I don't think hot drinks are usually administered to those organs.
I don't know how much hot chocolate warms you after an hour of shoveling snow, but it seems to help you feel better.
I've never heard of hot drinks cooling you off, either. Though it may explain an experience I had that's left me scratching my head for nearly 20 years.
I once helped some Ukrainians clean up their dacha (summer farmhouse) in June. Not scorching, but a decently hot day. The owner called a break and offered some "refreshment" in the form of dry cookies and hot herbal tea.
I don't begrudge them the cookies as that's what you get from the store sometimes, but I couldn't figure out the hot tea in the middle of the summer. I wonder if this theory is the reason. Then again, Ukrainians were generally averse to cold drinks, at least in my experience.
Post a Comment