How Long for Frostbite to Set In?

[Umbran]

ACtually all of the above posts are slightly wrong, becuase the real answer is...it depends.

All of those who don't also amount to "that depends" at least. Which a couple do.

In your case though, frostbite was much less of a worry than immersion foot (or in this case hand). It is a condition also known as trenchfoot (can you guess why). The extremity is submerged or even damp and then exposed to extremely cold temps (below 50) for extended periods of time (usually in excess of an hour, but can be considerably less do to other factos).

Two inaccuracies -

1)Cold and damp is often not sufficient. Trenchfoot generally also requires constriction of the extremety - like being in a combat boot. If the extremety is not constricted, it takes a lot longer for the condition to develop.

2)Trenchfoot does not require "extreme" cold - it can happen in conditions up to 60 degrees Farenheight. It was fairly common in Vietnam, which has winter average temperatures in the high 50s.

 

[Pbartender]

Actually, you can technically get frostbite without actually freezing the tissue, though thoroughly frozen tissue is the norm...

Frostbite (congelatio in medical terminology) is the medical condition whereby damage is caused to skin and other tissues due to extreme cold. At or below 15° C (59° F), blood vessels close to the skin start to narrow (constrict). This helps to preserve core body temperature. In extreme cold or when the body is exposed to cold for long periods, this protective strategy can reduce blood flow in some areas of the body to dangerously low levels. The combination of cold temperature and poor blood flow can cause tissue injury. Frostbite is most likely to happen in body parts farthest from the heart, and those with a lot of surface area exposed to cold. These areas include the toes, fingers, ears and nose. It is related, but not identical, to hypothermia.

That's why in minor cases of frostbite, the affected areas can be carefully thawed out and revived without much permanent damage... the flesh is not necessarily completely frozen.

In the cases where the flesh is actually frozen through, it remains dead flesh upon thawing, and must be removed lest gangrene set in... Those are the instances in which fingers, toes and ears are amputated.

 

[Thunderfoot]

<SNIP>
2)Trenchfoot does not require "extreme" cold - it can happen in conditions up to 60 degrees Farenheight. It was fairly common in Vietnam, which has winter average temperatures in the high 50s.

Actually I believe I said below 50. (although 60 is rare I can give you that one. )
In Vietnam the average was in the 50's, meaning the mean was lower. Constriction does cause it to onset much quicker, true, but there are always exceptions. Frankly, the temp and exposure in this case was so slight, that only other mitigating factors would cause any cold-weather injury (trenchfoot, frostbite, hypothermia or chillblain.).

But thanks for the corrections, I always appreciate the help.

 

[Thunderfoot]

<SNIP>
In the cases where the flesh is actually frozen through, it remains dead flesh upon thawing, and must be removed lest gangrene set in... Those are the instances in which fingers, toes and ears are amputated.

Usually in those cases, the skin turns black and waxy and is easily recognizeable. (though this isn't always the case.) In cases where the skin is blue tinged, professional medical care should be sought, becuase it can go either way.