Thursday, January 29, 2009

Ruminations of the temperature sort

Last night, while "shoveling" the slushy concoction from our driveway, I came to an unexpected realization: My cold weather tolerance has returned.

We've already had some bona fide cold weather this winter, with multiple sub 20 degree F days, and some nights in the single digits. And I really haven't felt terribly cold. This stands in contrast to much of the time spent here in Massachusetts, where I was always freezing. A breath of Canadian artic air would send me running for the long underwear.

And yet, I wasn't always like this. I grew up in Connecticut, which though not particularly cold is far from tropical. Then I went to college in Chicago- Ah, I remember the day, trudging to a morning class, where the air temp was -25 deg F (-50 with wind chill). Overall, I remember the cold as being present, but no big deal.

Then, I started grad school at Stanford. Palm trees! Orange and lemon trees! Chelsea Clinton! I wore shorts EVERY day that first winter. It was the El Nino year, and it rained every fricking day, but I still wore shorts. I distinctly remember the odd looks I received from those Palo Altans. They'd be wearing their hats and gloves, and I'd be traipsing across campus, bare legs and all.

But then a funny thing happened the next winter in California. I froze my ass off. I had to wear pants all winter, and even turned up the electric baseboard heat in my on-campus apartment. WHAT? Apparently, a year of living West Coasterly obliterated any and all cold tolerance I had built up. A reversal that took about 10 years to reverse.

Which brings me to what prompted me to even post this bit of boring biographical information: Is this a real phenomenon, and if so, what's the neurobiological basis for it? Do people in different geograpical locales actually perceive temperature differently? Is the difference peripheral (i.e. sensory neurons) or later in the processing? For example, what would you see if you compared the sensory neuron activity of lifelong resident of Alaska and Florida, recording their sensory neuron activity? And how does that change?...trp channels?? trp channels?? trp channels??...And is there a sex difference in this aspect (how many of us can recount the differences between our sense of temperature versus our partners?). And how does aging impact this?

The final question is:when will Spring arrive? Cause though I don't mind the cold so much, I'm already sick of the snow.


Eric Wilde said...

I can't take cold at all; but, then again, I grew up in Florida and now live in San Jose, CA.

VMH said...

I couldn't find anything by googling but I remember reading that when you live in a hot climate (i.e. Arizona) your skin changes to increase the amount of cooling. I don't remember the exact mechanism.

All I know is that when I go home to Buffalo in the summer and sit on my parent's deck at night when it is 70 F out, I need to put on a jacket. However, the difference in humidity has something to do with that as well.

But yes, your body does adapt.

Dr. Jekyll and Mrs. Hyde said...

Ohhhhh yeah. Native northeaster, moved to California and mocked people hideously for shivering at 55 degrees.

Then the second winter rolled around. Ate every single one of my words, in an effort to keep warm.

I'd go with skin circulation changing--something in the blood vessel dilation maybe. Homeostasis is amazing like that. Could be trp channel expression--but I can't see much advantage of upregulating them in a warm climate, for example.

Nat Blair said...

@Eric - Well, you can be the first subject in the "warm weather lifetime" group in our neurophysiological tests!

VMH: Ah, the skin strikes again. As a neurobiologist I'll admit that I had one conceived of neuronal mechanisms to generate this, but the increased cooling via the skin is a interesting one. If true, I'd guess that there's a neuronal mechanism anyway, as the sympathetic (or parasympathetic? who cares) nervous system can control sweat production, which would cool the skin by evaporation.

@DrJ - Great, n=2. Significance testing here we come. Interesting that there's another case similar to my own. My strong suggestion is to stay in California for apparently it takes 10 years to recover cold tolerance. But blood vessel dilation is another great hypothesis for the adaptation mechanism!

Maybe I'll actually have to try and do some searching on this. Somebody has to have studied it, right?