do flashlights run cooler in your hand?

do flashlights run cooler in your hand? or standing up exposed to open air? reason i ask is hect human body is 98.6

Yes they run cooler in your hand because your hand (blood) acts as a big heatsink and transferring the heat.

...but your hand will run hotter! /ubbthreads/images/graemlins/wink.gif

Holding a light in your hand can do ALOT to cool a light down.
Even though you hand is warm, the blood circulating through you hand acts just like a cars radiator system.

Alot of the mods here on CPF are NOT ment to turn on and sit down somewhere.
Especially the small ones, like very high mA Arc LS mods.

cool that makes sence.and lol at hotter running hand /ubbthreads/images/graemlins/smile.gif

A hot flashlight is definitely a lot hotter than the blood flowing throught your hands. Having the light in your hands will cool it down just like how an engine radiator works to cool down the engine.

But I believe that cool wind blowing through your lights would cool it down faster than your hands would.

conduction is more efficient then convection in some cases
imho
Chris /ubbthreads/images/graemlins/grin.gif

Of course it is true but not always. In tropical Singapore we don't experience the four seasons. But I have tried placing my L5 in front of the air-conditioner with the light turned on just to test if the light will heat up faster than the air-conditioner will cool it. After half an hour the L5 is still going strong and it is very cool.

What I want to highlight here is that convection can and will be better than conduction in wintry condition. How effective convection performs depends very much on climatic and atmospheric condition.

[ QUOTE ]
pjandyho said:What I want to highlight here is that convection can and will be better than conduction in wintry condition. How effective convection performs depends very much on climatic and atmospheric condition.

[/ QUOTE ]
There is a marked difference between the temperature of the air coming from the air conditioner and the temperature of you hand. That will make a big difference in the cooling. Blow air over the light that is at 98.6 and see how cool the light remains. It would also depend on the amount of airflow you can get over the light.

There are many factors to be considered when cooling the light. It is not an easy answer.

After my silliness with the warm running hand and what others have said, I think this will sum it up...
If it's cold outside, the flashlight will be cooler in the air than in your bare hand. If it's warm or hot outside, your hand will cool it better. Sound good?

Precisely what I meant...