Thermodynamics of peeing?

[BrunoPuntzJones]

I've been trying to come up with an answer for this.

Say you are sitting in your house. You're hot, the ambient temperature is 74F. You have to pee really bad, so you go tinkle out a quart.

Does this have any "cooling off" effect by losing 1 qt. of 98.6F body weight?

Could it actually make you warmer in the sense now that you've lost that quart, your body is gonna have to step up and replace the heat lost through that quart?

I figure it doesn't make any different at all though. Kind of like a coffee dispenser. It's 74F in the room, the coffee is say 130F. You dispense a cup, but the temp of the coffee inside is still 130F, it doesn't get magically warmer or colder.

Does the plane take off?

 

[theprodigalrebel]

This should be a classic thread.

 

[radioouman]

hmmmmmm

 

[dullard]

I have pondered this myself over many a urinal. Hey, you have to think about something, and I'd rather wonder about thermodynamics than to stare at the wall (or far worse the guy next to me.)

The thermodynamics are pretty simple in this case. If a body is hot, removing a portion of that body will not suddenly change the body's temperature. It'll still be hot afterwards. However, since you are in a cool room (74°F), you will cool down FASTER if you pee compared to if you hold it in. So, yes, pee away in that case. But, if you are hot and you are going to be outside in 100°F weather, temperature wise you should keep it in (health wise this isn't a good idea).

Then we can get into the unpleasant topics of if you miss the urinal and hit your own leg. That changes all of my conclusions above. But I don't want to make this otherwise classy topic dirty with discussions of that idea.

Note: as a further complication, removing your pants to pee in a 74°F room will help cool you down. But that can be done aside from peeing and thus should not be an issue worth considering in this thread.

And of course, the plane takes off a treadmill as the treadmill has nothing to do with the motion of the plane.

 

[theeedude]

Your body will stay at same temperature, but your peepee will warm up from the warm wee going through it.

 

[sixone]

You lose more heat from your head while doing nothing, than you do from peeing.

 

[Eli]

Originally posted by: dullard
I have pondered this myself over many a urinal. Hey, you have to think about something, and I'd rather wonder about thermodynamics than to stare at the wall (or far worse the guy next to me.)

The thermodynamics are pretty simple in this case. If a body is hot, removing a portion of that body will not suddenly change the body's temperature. It'll still be hot afterwards. However, since you are in a cool room (74°F), you will cool down FASTER if you pee compared to if you hold it in. So, yes, pee away in that case. But, if you are hot and you are going to be outside in 100°F weather, temperature wise you should keep it in (health wise this isn't a good idea).

Then we can get into the unpleasant topics of if you miss the urinal and hit your own leg. That changes all of my conclusions above. But I don't want to make this otherwise classy topic dirty with discussions of that idea.

Note: as a further complication, removing your pants to pee will help cool you down. But that can be done aside from peeing and thus should not be an issue worth considering in this thread.

:laugh:

:thumbsup:

 

[SirStev0]

Your urine is not causing or maintaining your body temperature. Removing it will do nothing.

 

[Howard]

Your body temperature will not change unless the temp of your body is not uniform.

 

[Kelemvor]

I don't think it has an effect although it sometimes makes me shiver.

The thing to remember is the urine is not heating the body, it's the other way around. All you are doing is removing the warm liquid. You're not replacing it with cold liquid or anything like that.

 

[crt1530]

Originally posted by: Eli

Originally posted by: dullard
I have pondered this myself over many a urinal. Hey, you have to think about something, and I'd rather wonder about thermodynamics than to stare at the wall (or far worse the guy next to me.)

The thermodynamics are pretty simple in this case. If a body is hot, removing a portion of that body will not suddenly change the body's temperature. It'll still be hot afterwards. However, since you are in a cool room (74°F), you will cool down FASTER if you pee compared to if you hold it in. So, yes, pee away in that case. But, if you are hot and you are going to be outside in 100°F weather, temperature wise you should keep it in (health wise this isn't a good idea).

Then we can get into the unpleasant topics of if you miss the urinal and hit your own leg. That changes all of my conclusions above. But I don't want to make this otherwise classy topic dirty with discussions of that idea.

Note: as a further complication, removing your pants to pee will help cool you down. But that can be done aside from peeing and thus should not be an issue worth considering in this thread.

:laugh:

:thumbsup:

The bladder is more or less a closed system vessel. Once the liquid is in there it will not be used by your body. Holding the liquid in your bladder will not prevent dehydration. It will only make you uncomfortable.

If it's hot out, drinking cool water will lower your temperature and is more readily absorbed by the body than warm water.

 

[BrunoPuntzJones]

I know it won't be an instantaneous "relief." Is the bladder taken into account with body temperature? I mean does the temp of the bladder have any relation to body heat? Or does it just reach equilibrium with the body because it is "touching" it?

If i filled up a big gulp while driving down the road, the total temp of the inside of the car won't change. But if I were to pour it out the window the car would have less to cool would it not?

The above not being related to the original question really...

 

[EarthwormJim]

You're decreasing your heat, however your temperature would not drop since it is constantly kept at roughly 98.6 F.

Similar idea as sweat, just less effective since more heat is lost through evaporation.

 

[arcas]

If you miss the urinal and hit your leg, then an evaporative cooling effect takes place. Thus, if you're hot and you have to pee, pee on your leg.

 

[crt1530]

Originally posted by: BrunoPuntzJones
I know it won't be an instantaneous "relief." Is the bladder taken into account with body temperature? I mean does the temp of the bladder have any relation to body heat? Or does it just reach equilibrium with the body because it is "touching" it?

If i filled up a big gulp while driving down the road, the total temp of the inside of the car won't change. But if I were to pour it out the window the car would have less to cool would it not?

The above not being related to the original question really...

By the time the liquid has reached your bladder, it will have reached equilibrium with your internal body temperature. Peeing will not affect your body temperature at all (unless you have to pee so bad that you're sweating).

arcas does have a point. If you're really trying to cool yourself off, pissing on yourself and letting it dry will cool you down.

 

[manowar821]

Originally posted by: arcas
If you miss the urinal and hit your leg, then an evaporative cooling effect takes place. Thus, if you're hot and you have to pee, pee on your leg.

lmfao :laugh:

 

[Steve]

Originally posted by: SirStev0
Your urine is not causing or maintaining your body temperature. Removing it will do nothing.

Exactly the point I was going to make. The urine is not coursing through your bloodstream, thus not carrying 98.6 F temps throughout your whole body.

Draining your body of blood on the other hand, makes you feel cold.

 

[manlymatt83]

Originally posted by: senseamp
Your body will stay at same temperature, but your peepee will warm up from the warm wee going through it.

 

[SlowSpyder]

<--- Highly Technical.

 

[Gibsons]

When you urinate, your surface area to mass ratio will increase slightly, allowing you to cool off a bit faster. In theory anyway. But the actual act of urination won't change your core temperature.

 

[Canai]

Wouldn't the increased surface area of ~98.6º liquid cause the room to warm slightly?

 

[SoulAssassin]

This thread makes me want to start drinking.

 

[Goosemaster]

*assuming that you've been holding it in way too long*

my response based on years of arduous experimentation:

I've noticed that that induces stress, which raises the heart rate, and increases heat production.
Relative to the ambient tempaerature, my skin and such are not at 98.6F , or at least do not feel that way.
Havng the urine that has been INSIDE my body travel thorugh my hoohah acutally heats up skin that was acutally colder, and after the deed is done, as my hoohah begins to cool off.
I then feel the heat from my body graviating towards the cold, and along a with the decrease in heartrate, provides a cooling effect as your body isn't being overwhelemed anymore.

.....not that that is anything more than conjecture based on the many times that've been stuck on rt. 66 regreatting, painfully, the last exit that I did not take before reaching gridlock...

 

[Goosemaster]

Originally posted by: Eli

Originally posted by: dullard
I have pondered this myself over many a urinal. Hey, you have to think about something, and I'd rather wonder about thermodynamics than to stare at the wall (or far worse the guy next to me.)

The thermodynamics are pretty simple in this case. If a body is hot, removing a portion of that body will not suddenly change the body's temperature. It'll still be hot afterwards. However, since you are in a cool room (74°F), you will cool down FASTER if you pee compared to if you hold it in. So, yes, pee away in that case. But, if you are hot and you are going to be outside in 100°F weather, temperature wise you should keep it in (health wise this isn't a good idea).

Then we can get into the unpleasant topics of if you miss the urinal and hit your own leg. That changes all of my conclusions above. But I don't want to make this otherwise classy topic dirty with discussions of that idea.

Note: as a further complication, removing your pants to pee will help cool you down. But that can be done aside from peeing and thus should not be an issue worth considering in this thread.

:laugh:

:thumbsup:

comedy gold*:laugh:


*

 

[Goosemaster]

Originally posted by: Canai
Wouldn't the increased surface area of ~98.6º liquid cause the room to warm slightly?

*paging newton*