I was a guinea pig for wind chill!

Pierre Tourigny

In May and June 2001, thanks to a coincidentally well timed period of leave I was able to participate in the clinical trials of the new wind chill model (facial cooling) on human subjects, which were held at DND's Defence and Civil Institute of Environmental Medicine (DCIEM - now named Defence R&D Canada - Toronto) in Toronto (about 4 km south of the Environment Canada building).

Photo of Dr. Michel Ducharme, physiologist responsible for this research, installing instruments on my face

The trials consisted in four (five, actually, as one had to be redone) walks on a treadmill (4.8 km/h) in a wind tunnel: one walk at each of -10°, 0° and +10°C, plus a "wet trial", at +10°, which had an additional twist: a light one-second splash of water in my face every 15 seconds.

Each walk lasted 90 minutes - 30 minutes for three different wind speeds: 2, 5 and 8 m/s (or about 8, 18 and 29 km/h, respectively). Before the trials, there was first a physical exam (the doctor was a colleague's uncle - it's a small world!), and a familiarization session in the wind tunnel, with the rectal probe used to measure internal temperature. As it turned out, the rectal probe was just a narrow flexible cylinder (diameter of less than 5 mm), which I felt for about 5 minutes at the most.
There were also several other sensors to measure the temperature and the heat transfer at different points in my face: one on each cheek, one on my forehead, one on my chin, one on the tip of my nose, and even one in my mouth (on the inside of my cheek) to measure the temperature difference between the two sides of the cheek. In the end, it was the mouth probe that I found most annoying because it prevented me from opening my mouth. You should have seen me with all these sensors and wires: I looked like a robot (see photos). But overall that was a very good experience: I had never tried medical research before, and it was most educational to see how DCIEM operates.

The trials made me realize the real sensation of wind chill. At -10°, for instance, while my face really felt cold for the first several minutes when the wind went up, e.g. from 5 to 8 m/s, after about 5 minutes, my body began to adapt and the feeling of cold subsided. After 15 minutes, there was not much difference compared with the lower wind speed. Clearly, it seems there is a biological mechanism that fights cold, and quite well at that. I'm eager to see the actual, quantitative results of skin temperatures and heat transfer to see if they match my qualitative feelings. As for the rest of my body, it stayed reasonably comfortable thanks to the heavy military clothing we were wearing for the tests. Curiously, I felt colder during the test at 0°, probably, I think, because of the less heavy clothing I had then.

The other trials were better. At +10°, the trial went like a breeze. The last one, the "wet" trial (with "drizzle"), I had a surprise at each spray, at least for the first minutes. Let me just say I was glad they did that trial at +10° and not at 0° as was first envisaged: the water really felt cold at times!

Participating in these trials was really an experience. I'd like to do more for DCIEM research if I ever get a chance. But for now, I hope our new program will fulfill its objectives and help Canadians face the cold.

Pierre Tourigny is a meteorologist with the Meteorological Services and Business Policy Branch of MSC-Headquarters.

Meteorological Service of Canada - Environment Canada - Government of Canada

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