Why do my ear lobes get hot in cold weather?

February 5, 2006 11:43 AM

Why do my fingers and ear lobes swell and get hot in cold weather? Is there a medical term for this phenomenon?
posted by F Mackenzie to health & fitness (5 comments total)

It would seem your body is supplying more blood to these areas to 'warm' them up. Yes?
posted by AllesKlar at 12:26 PM on February 5, 2006

Sorry, I suppose this is more apt Raynaud's phenomenon.
posted by AllesKlar at 12:29 PM on February 5, 2006

It's likely a result of cold-induced vasodilation. (Raynaud's usually indicates really cold extremities, even when your surrounding temp isn't that cold. Watch out for friends with Raynaud's, because they will stick their death-cold hands and feet on you to leech away your heat any chance they get.)

your body's initial response to cold: vasoconstriction of the blood supply to the skin to limit loss of heat across the skin (hence the pallor your skin gets in the cold).

but to prevent the extremities from frostbite, a little while afterwards you experience a cold-induced vasodilation to the peripheral circulation, so the skin of your nose, fingers, toes, and ears get a rush of blood delivered to them. Hence the warmth. The length and magnitude of the vasodilation phase is variable; perhaps yours is longer/stronger?

If you have a lot of swelling, you might have increased permeability in your capillaries (that is, it's easier for fluid to go out into the surrounding tissue), which can result in a slight edema.

p.s. Wear your gloves when it's cold out! And a hat!
posted by neda at 12:49 PM on February 5, 2006

Thanks, neda. Just what I was looking for. Further digging found revealed:

Cold-induced vasodilation (CIVD) in the finger tips generally occurs 5–10 min after the start of local cold exposure of the extremities. This phenomenon is believed to reduce the risk of local cold injuries. However, CIVD is almost absent during hypothermia, when survival of the organism takes precedence over the survival of peripheral tissue. Subjects that are often exposed to local cold (e.g. fish filleters) develop an enhanced CIVD response.
posted by F Mackenzie at 8:26 PM on February 5, 2006

Part of Raynaud's includes very hot-feeling fingers when they start to warm up. I have it.
posted by IndigoRain at 9:40 PM on February 5, 2006