If it’s cold outside, and you pee, does it lower your body temperature?
Not my question, it’s from my business partner…
My guess is that it doesn’t lower your temperature, but I’m not sure.
Certain parts of your body might get a little chilly.
The pee wasn’t heating you - you were heating the pee. Now that you don’t have to heat it, your heat can go to other uses (although the gain would be negligible). Also, If you had to pee really bad, now you don’t have to expend calories carrying the extra weight, twisting your legs together and constricting you pee muscles.
no, but here’s the deal. think of it this way- you and the urine are separate parts of the same system, even after evacuation.
Your whole mass has a temperature. And it’s radiating away into the bitter chill. Once the urine leaves, the temperature of the whole system will drop significantly- the urine melts the snow and gets cold.
But now you have less mass. Sure, not a lot less, but a smaller mass will radiate heat away faster (sure, maybe imperceptibly faster, but so what).
jb
p.s.- sometimes I get the chills when I pee and I had to go really bad- even if it’s inside. So maybe he’s just got the chills
p.p.s.- when the chills get really extreme, it feels as if I’m wearing an old 70s pair of quarter-inch jack HeadPhones.
I think an important distinction is the difference between heat and temperature. Heat is a sum total of a particular type of energy, whereas temperature reflects the average kinetic energy of a substance. If you have 10 liters of water at 37 degrees celcius in an insulated container, and you dump out 5 liters into a snow bank, the temperature of the water in the container remains at 37. However, along with half the water, half the total heat has been lost.
I believe that’s known as piss shiver.
I don’t think this is a dumb-ass question. I think a dumb-ass question would be, “How do I post a question to the Straight Dope Message Board?”
If you spend any time in harsh outdoor conditions, while mountaineering or winter backpacking for example, it’s a damn good idea to pee before settling into your mummy bag for the night. Two reasons, #1 so you don’t have to stumble around in the dark and slip off the mountain (it happens), and #2, so you don’t waste energy heating the unnecessary fluids, energy better spent warming your muscles and extremities. I don’t know if it makes your temerature rise, but I do know that it reduces your calorie expenditure.
Yes it does happen! It happened to a friend of mine a few years back actually. And though they say he fell serveral stories, he wasn’t killed on impact. His girlfriend found him dead the next morning. And yes, it was a closed casket… :eek:
ANYWAYS, what i was going to say is, FWIW, if i’m ever cold (usually at work), i go pee and it warms me up quite a bit… 
-Dani
It’s that “Tommy Two-Tie” again, isn’t it, Astroboy?
Crucial point: subjective feeling of warmth or chilliness is not necessarily indicative of body temp. Everyone has had the experience of being sick with a fever and alternately feeling very chilly and quite a bit too warm. Well, the chilliness marks the time when your temperature is rising. The overly warm feeling coincides with your temperature going down.
Why does peeing warm you up? I have no freaking idea. I’m suggesting, however, that there needn’t be any association with your core body temp.
This makes little sense to me. Your rate of heat loss varies as a function of (1) the difference between your temp and the outside temp (2)your surface area (3) factors like insulation which slow heat exchange (4) factors like wind which speed heat exchange (5) your circulatory patterns which try to shunt blood to the skin when you’re warm (to radiate heat) and shunt blood away from the skin when you’re cold (to prevent radiative losses).
There’s no need to “heat unnecessary fluids,” because they’re already hot. Urine is preoduced at body temp and maintained at that temp. Urine is stored within the body core (urinary bladder, located in the pelvis) and the presence of urine in the bladder should do nothing to increase radiative heat losses. The only way that storing urine would increase calorie expenditure is if it’s presence increased radiative heat loss.
Say you set up an experiment. Run a line into and a line out of your urinary bladder. Connect the lines to an aluminum radiator and immerse the radiator in a bucket of ice water. Start the flow of urine through the radiator and back into your bladder. This cooling circuit will rapidly cause you heat loss. If you emptied your bladder in this case, thus disrupting the flow of urine to the radiator, you’d greatly slow the heat loss. If the heat in your urine is not appreciably radiated, however, retaining the urine will not affect your rate of heat loss
I’d really like to see a (fairly scientific) camping source that explains how peeing confers an advantage for heat retention.
A wilderness instructor of mine told us that if it’s cold, and we have to piss, we should piss. This is because your body makes a top priority of keeping your piss warm, since if it freezes, well, that’s bad news.
Pissing, then, frees up some energy for the rest of your body.
I would normally agree with choosybeggar, but I dunno. I think that your body doesn’t have to heat
the urine. After all, it’s distilled blood, blood which was at body temperature before. It was pumped and shunted through body parts metabolating at normal temperature. It’s held in a muscular core surrounded by fatty tissue and skin, in close proximity to the warm guts and hotter naughties.
And I’d disagree with Friedo, because if the temperature of your urine were anywhere close to freezing, you’d probably be dead anyway. Having a pissicle in your bladder wouldn’t be a bother.
But, and here’s a but, what about the energy a distended bladder uses for muscular contractions? It may take an appreciable amount of ATP to keep those muscles taut. And in fact, when you get colder, and the body is trying to divert resources to core functions, perhaps bladder action is one of the first systems Scotty shuttles. So you really really have to go.
I dunno. There’s so many what if’s and suppose’s.
jb
The body heats the pee because the body heats the bladder. If you distinguish between heat and temperature, peeing in the cold should lower the first and raise the second, but I think the changes would be small.