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Scientists Identify How the Body Senses Cold
Vicissidude writes with a link to a story on the Nature website, discussing the discovery of a protein that may enable us to sense cold temperatures. It's been pinned down in mice, and the same protein may perform a similar function in humans. Mice rely on a single protein, called TRPM8, to sense both cold temperatures and menthol, the compound that gives mints their cool sensation. The sensor also controls the pain-relieving effect of cool temperatures, but does not seem to play an important role in the response to painfully cold temperatures below 10 C. TRPM8 is in the same family as the protein that detects heat and capsaicin, the compound that makes peppers hot. These proteins lie in the cell membranes of select neurons, and form channels that open and close in response to external signals."
I'm not sure if skin/nerve temperature is the answer either.
Frostbite, or even actual freezing of the extremities, can occur with only a "pins and needles" feeling beforehand, although in some cases there is throbbing and aching. (link)
Since the skin and nerves would have to drop through the 10C (50 f) temperature range before freezing, I don't really see what they are basing their "painful" temperature on. I would guess it is a sustained temperature in that range, but the article doesn't give enough information to really tell.
Reading code is like reading the dictionary - you have to read half of it before you can go back and understand it.
Although the body fat content probably is a factor, I think this is more interesting in respect to researching pain management in general. Some people (regardless of fat) can not handle pain very well at all. Others can live with a great deal of pain with no medication.. For instance, many years ago I had a motorcycle accident which destroyed my knee, and had to have surgery to rebuild it.. I have been in pain ever since, but I have learned to ignore it, and don't think about it.., it is just the way it is.., and I don't take any medication for it.. I have met other people who stub a toe, and run to the emergency room for vicodin... Perhaps these proteins work harder in some people than others.. The people like this who can't handle the most minor of pains, end up as pill junkies if they are not careful. If it is possible that these people could be relieved,or at least be made to better tolerate pain without narcotics they would be a whole lot better off.
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Last year on my second year medical course I wrote about TRPM8 being the cold receptor. It's on my course again this year as well on TRP channels in vertebrates AND mentioned in my course on nociception.
Not only is it not new, but it's not desperately interesting. Other receptors like TRPA1 are involved in properly cold sensation, it's thought, TRPV1 in moderate-warm sensations (thats what capsaicin stimulates to make food hot) and TRPV2 is thought to be for properly hot.
Any proper neuroscientist has known about TRPM8 for literally years, this changes very little!