I like REALLY cold drinks, with lots of ice in them. I am a small person; frequently by the time I finish up the ice at the bottom of my drink, I feel hypothermic, shivering uncontrollably.
I know a number of things can affect the metabolism - exercise or the lack thereof being the main one, but also the amount of food one consumes (too little and the body goes into starvation mode and conserves every calorie it can), but what about cold and heat? Do repeated bouts of cold such as one might get from a huge Slurpee…affect the metabolism, either to slow it down, or to speed it up? What about excess heat?
I’ll let others with more expertise correct me if I’m wrong, but I think the cold drink has the effect of lowering your core temperature - it’s icy, and it’s directly in the middle of your trunk in your digestive tract. I would suspect that, if anything, it would cause a short increase in your metabolic rate so that the excess heat from metabolism would raise your core temperature again.
Your body assumes everything is cold once your core gets cold, because usually the core would be the last part of your body to feel the cold. That’s why the shivering - it won’t do the core any good, but it’s a good reaction to overall cold.
Although cold does slow down your metabolism, I find it hard to believe your cold drink is doing this. If your body is the equivalent of sixty litres of 99 degree water, adding a pint of forty degree water wouldn’t have a big effect on the overall temperature. Drinks like Slurpees are cold, and big, but also high in sugar. A drink sufficiently big and cold theoretically could make you feel cold and shiver; but the sugar would release heat and energy when broken down by the body over the next hour or so.
I don’t know that it’s all that useful to treat the body as a homogenous body of fluid with respect to temperature (or, for that matter, anything else such as concentration of certain solutes). Much of that fluid is sequestered and doesn’t move around, and the body’s design is significant in that there are a variety of barriers to fluid moving rapidly from one part of the body to the next - for example, the pericardial cavity is separate from the peritoneal cavity. Blood is one fluid that does flow rapidly from one part of the body to the next, but its volume is considerably less than 60 L, and its average temperature is less than 99 degrees what with the amount of blood near the body surface and in the extremities.
How much fluid is the blood and at about what temperature? Then maybe we need to consider the fluids in and around the digestive tract?
That being said, I can’t with any confidence say that the metabolic rate would actually change … but I’m asking, do you think those factors would make a difference?
I don’t think we need to treat the shiver as theorhetical - the OP is asking because s/he noticed it.
… but I’m asking, do you think those factors would make a difference?