Haven’t we already had a thread (or column) about how many calories are burned by heating up cold drinks (A: Not many, IIRC). I’ve alway been told that hot beverages and hot peppers increase sweating.
So where does that energy come from?
Maybe in the Eastern cultures sweating was historically the only way to cool down. This could have been due to several factors alone or together:
• indigenous peoples’ propensity NOT to perspire?
• lack of natural cooling factors such as wind?
• acknowledgment of a precious mineraloid composed largely of hydrated silica?
That’s what I remembered, too, but I read this yesterday, and I’d like to find the actual report:
150 calories isn’t a whole lot, but it’s probably 10% of what a thin woman eats in a day.
Your body is performing metabolism constantly, and it produces tons of heat in the process. Humans have lots of mechanisms to regulate their temperature - stuff like sweating, controlling bloodflow to the skin and the extremities, shivering, and so forth. Most of those mechanisms don’t require much energy; it’s only when you’re shivering that you’re actually engaging in extra metabolism in order to warm up. Otherwise, whatever you drink enters your body, reaches temperature equilibrium with the contents of the body, and so on. A single glass of water is not going to cool you off all that much; if you’re already too warm - warm enough to sweat - then why would your body produce more heat and burn more calories in order to compensate for a cold glass of water? You might sweat a bit less until your body warms up again. That’s all your body has to do to compensate.
What metabolic process do you imagine to be happening that warms up your food? There’s not a little heater in your esophagus that warms up everything you swallow.
Okay, the version my mother told me when I was a child is that hot drinks open the pores on the skin, allowing you to sweat more. Sweating carries toxins out of the body, so youfeel better. cold drinks close the pores, and stop you sweating. That’s what I was told, it might be an old wives tale.
As for the body heating up iced drinks, raising 1 cc of water by 1 degree centigrade equals one calorie. however, the energy content of foodstuffs is measured in Kilocalories. So, raising the temperature of cold drinks does not make a noticeable dent.
I think the point is that any hot object coming into contact with a cold object will lose heat. Thus a cvold drink swallowed will absorb heat from the surrounding human body, and the body will lose heat, thus it must expend energy to maintain its owntemerature.
AIUI, this is true, but the effects are tiny.
The body regulates its temperature through a lot of means that don’t involve directly expending calories (at least not in any significant number.) That’s the point that people seem to be failing to understand. If the body is already working to get rid of heat - by sweating, for instance - then all it has to do to maintain its temperature after drinking a glass of cold water is to not get divest itself of quite as much heat.
But that’s the exact opposite of what I said. After drinking a cold drink theliquid absorbs body heat. The body becomes colder. Thus must heat itself up to maintain constant body temerature.
What mechanism exists for heating itself up without expending energy?
It’s the exact opposite of what you said because what Excalibre is saying is right and what you are saying is wrong. 
The body does not have to heat itself up to maintain temperature. It is already trying to get rid of heat to maintain temperature (because it’s hot, as per the OP). The cold glass of water helped it get rid of a little bit of heat effortlessly. Why would this require the expenditure of energy?
Imagine a really hot rock. Imagine pouring cold water on this hot rock. Did the rock have to expend energy to heat up the water? No, thermodynamics takes care of that.
But if you’re too hot already, your body doesn’t need to expend more energy to make the drink hotter. It uses up some of that “too hot” energy to warm the liquid, instead of expending more energy to sweat, is what Excalibre’s saying. The body doesn’t get colder enough to *need *to warm itself, unless you’re drinking an unlimited supply of ice water.
Look, if I have a pot of steaming hot water and I add an ice cube, the water will stay hot while the ice cube melts. It may no longer steam as it cools a little bit, just like you may stop sweating as the excess heat in your body warms your iced drink. I could put my pot over a fire and add extra energy to keep it steaming *and *melt the ice, but there’s plenty of excess heat in the water to melt the ice on its own. If I keep adding and adding ice, then sure, eventually the pot of water will get cold and I’ll need to put it over a heat source to warm it again. But just one ice cube won’t lower the level too far - just like the body temperature of a sweating person isn’t cooled too far by a glass of ice water.
Or, you may turn on your ceiling fan to cool your living room. Turning on the ceiling fan uses energy, but you can then turn off your air conditioner, which also uses energy. Warming cold liquid and sweating both require energy, but you may not need to do the sweating if you have the cold liquid. Without the fan (cold liquid), you’ll use the same or more energy on the air conditioner (sweating.)
Now, if you’re not hot enough to sweat (or for some other cooling mechanism by your body), then your body may indeed need to expend extra energy to warm a cold drink. It may not have extra “too hot” energy to use.
I’m not sure if **Excalibre **is correct, but I get what he’s hypothesizing.
It is well known that when the body’s core temperature drops, the body reacts by reducing circulation to the extremitys.
It doesn’t seem so far fetched that raising the core temperature with a hot liquid could well induce the opposite effect, and stimulate sweating as well.
The first effect frequently results in the loss of fingers and toes, and therefore got the attention of the medical community. The second effect (if it exists) is only a matter of comfort, and thus may not have recieved so much attention.
I remember reading some explanation of this practice, in fact I think I read the explanation on these forums some time ago.
Basically when you drink a hot liquid it heats up the contents of the stomach, this in turn heats up the blood in the vessels that surround the stomach (which I believe there are lots of). When the blood reaches the brain a temperature check is made, the brain makes note of the fact that the blood is of a higher temperature than it was a couple of minutes ago and takes appropriate action to regulate the temperature by inducing sweating and moving the blood vessels closer to the surface of the skin to aid heat loss.
I’m not sure how much scientific fact there is behind this thinking but it makes logical sense to me that if the temperature of the blood rises the body will take action to cool things down.
Nine new posts and still nobody’s noticed that
is just an extremely convoluted way of saying Hi, Opal!?
You science geeks have no sense of humor.