January 01, 2008

Frostbite in 1.2 seconds

When I was growing up in Saskatchewan, I would always be reminded by either the radio or my Mum to bundle up because I could "get frostbite in less than x minutes" or - if it was a particularly cold and windy day - "in less than x seconds." We spend a lot of time outside, and, while I never got frostbite, I got frostnipped many, many times. Sometimes, it didn't matter how much I bundled up; that prairie wind could blow!

When I was eight, I wondered who the poor fool was that volunteered to test how cold it needed to be at a particular wind speed to get frostbite in less than a minute. As I got older, I realised that the Frostbite-O-Meter people probably figured things out in a more scientific manner; one that didn't place anyone's epidermis in peril. I give scientists too much credit sometimes.

Two nights ago, I got a call from one of my neighbours. Through an unfortunate miscommunication, her kids were out of heating oil and needed an alternative heat source for the night. It was below -30oC out and the house was cooling rapidly. Did I have a heater they could use? You bet I did.

When I lived in Fort Liard, we had an old beast of a furnace. I constantly feared that it would fail in the depths of winter and that all of our plumbing would freeze. In the larger centres, it's not too bad, but in the communities, help could be a long way off if you couldn't find someone in town with a bit of experience. In Fort Liard, a good furnace repair person was at least a day away. If we lost the pipes, a plumber would have been nearly impossible to get.

Since we didn't have a wood stove (and getting one would have made the house uninsurable), I looked for alternative heat sources in the likely event of a power or furnace failure. I looked and looked and, one day while browsing the aisles of Weaver & Devore in Yellowknife, finally stumbled across a Coleman catalytic heater designed for indoor use. I got two.

I've used the heaters a couple of times and I've had other neighbours use them in home heating emergencies. Overall, I've considered them to be a good investment. So, when my neighbour's son showed up on my doorstep looking absolutely exhausted, I was glad to help.

I pulled out the heaters and the batteries for the fan, and got the little green propane tanks from outside where I stored them.

Outside, in the dim light on the front porch (since it's just plain foolish to light the heaters inside), I began to set one up so he could see how they worked. As I screwed the little green propane cylinder into the heater, I felt a gust of cold on my wrist and then a quick stinging sensation. There was something wrong with the propane tank and it had discharged the super-cooled propane onto the underside of my wrist.

I pulled my hand away and looked at my wrist. It was white and frosty. Tentatively, I touched it. The skin was frozen.

It didn't hurt, so I removed the bad tank and put a new one on, continuing with the demonstration. With that done, my neighbour's son left to, hopefully, keep his home from freezing.

I looked at my wrist again. The skin was thawing and had swollen. It started stinging as though I had burned it. I guess I did. It was a cold burn.

Two days later, my wrist is still red but is healing nicely. The swelling has gone down, though it's still tender to the touch.

While writing this entry, I stumbled across Environment Canada's windchill calculator and "Minutes to Frostbite" table. The quickness of my frostbite was off the charts, which leaves me wondering - just how cold was that propane, anyway?


George said...

Not sure on how cold the propane shot was but propane boils at something like -42c so I suspect its around that temp compressed.

FYI, you probably know this but if someone runs out of heating oil up here, there is only one different ingredient between heating oil and standard diesel fuel you buy at the pumps.... taxes.

A few gallons of diesel will get someone through the night.

Meandering Michael said...

They tried doing that, but the tank was drained dry, they got air in the line, and lost their suction. They'd been trying to fix it all day.

George said...

Ahhhhh, more than just a fuel issue then. Okey doke.

Meandering Michael said...

Yupperoo! Sorry I left that part out. It was for story-telling expediency.

I enjoyed your clever way of explaining the hidden secrets of home heating fuel, though!

Fawn said...

Turns out they just had to bleed the line a little - they didn't know, never having dealt with it before.

So if the propane was around -42 but flowing across your skin at, say, 2 or 3 metres per second, I I'd say there would be a distinct "wind" chill factor...

George said...

In the end, no matter what the temp of the propane was or its velocity leaving the container, the end result is the same.... owwie.