Heat loss through the head

[NH_Mtn_Hiker]

In searching for something else, I uncovered the following: "Frozen Mythbusters" http://www.box.net/public/static/lehlmxuu38.pdf. Some good info from three experts.

Doug

...now to add something constructive; In ref. to Myth #3, I tried carrying a thermos of hot chocolate with me on several hikes but I found the warmth it offered was very temporary compared to what I get out of a bottle of Mountain Dew. A couple 20oz bottles of Dew will keep me warm for 20 miles or more with little or no food, and it helps keep my feet working to. In addition, the caffeine comes in handy towards the end of a 20+ miler.

 

[randomscooter]

...now to add something constructive; In ref. to Myth #3, I tried carrying a thermos of hot chocolate with me on several hikes but I found the warmth it offered was very temporary compared to what I get out of a bottle of Mountain Dew. A couple 20oz bottles of Dew will keep me warm for 20 miles or more with little or no food, and it helps keep my feet working to. In addition, the caffeine comes in handy towards the end of a 20+ miler.

There ya go. My favorite is Coke, de-fizzed, diluted to 1/3 strength, and heated. This in place of water.

 

[Little Rickie]

My wife got me a spyder windstop fleece vest with a two way zipper!!! It has a turtle neck collar that will zip right up under my neck gator while I can zip up the bottom to vent my lower torso. Cool!!!

What a gal!

 

[DougPaul]

My wife got me a spyder windstop fleece vest with a two way zipper!!! It has a turtle neck collar that will zip right up under my neck gator while I can zip up the bottom to vent my lower torso. Cool!!!

I have both wind-blocking and regular fleece jackets. The wind-blocking fabric is far less permeable to moisture so you have to be careful not to let moisture accumulate under it. Once wet, the wind-blocking fabric is also slower to dry.

IMO, regular fleece and a separate shell is more versatile. (One should carry a hard shell with either type of fleece.)


A friend had a vest which was wind-blocking fleece on the front and regular fleece on the back. This might be a good compromise.

Doug

 

[Little Rickie]

It's a Christmas gift from my wife. It's perfect.

 

[weatherman]

I know one of the authors of this article (Carroll) pretty well, and indeed what's been stated already here is what he loves to do... debunk ideas like the 45% heat loss rule, just for the fun of pointing out that there ain't any data to substantiate it. The problem arises when people take messages like that to mean "there is no difference in the proportion of heat lost through your head"... which is not what the authors say. From experience, we all know that if you had to pick which 9% of your surface area to cover, it'd be your head (well, from a heat loss point of view...) so there must be some amount of heat disproportionately lost, but nobody has done a good-enough study to say how much, exactly, is lost. Not that it really matters, anyway.

Uh-oh, a new trend... hiking in only a hat.

Weatherman

 

[Mike P.]

I swear by the wind-bloc fleece, but as a vest just to keep core warm. I have the jacket too but moisture management was impossible.

I do carry a shell to go over just in case.

The body already has decided to keep blood flowing to the head as as people mentioned with the blodd vessels there, that heat loss is going to take place.

Does caffiene act also as a vaso-constrictor (right term? thinking of alcohol that makes capillaries open causing warmth sensation but counteracts the bodies defense of keeping the core warm) if so, the Dew would be a false warmth. as a diruetic it would cause you bladder to fill which until expelled, requires keeping at body temperture so additional energy used to heat urine.

(okay TMI)