February 17th, 2006

Aeris

Wind Chill

Yes, it's cold. I started thinking about the old wind chill charts after prettydark posted about the brutal temperature today. See, there used to be this chart up on the local weather channel during the winter which explained the different levels of wind chill and how dangerous they were. About five years back, they changed the system to give effective temperatures instead of the somewhat strange scale (watts/square meter, so 1700 was mild, 2400 was dangerous, etc.). However, I always liked the way the chart ended.. I wanted to get a t-shirt printed with just the wind chill scales and meanings on it. And then it vanished with the new system! But, lo and behold, the meteorological service of Canada has a online chart which describes the old system. Check out how far down the list you need to go before it's considered "Hazardous Conditions", and the advice for dealing with them (bold/underline emphasis mine):

Wind Chill Hazards and Risk of Frostbite
Wind Chill Risk of frostbite Health

Concern
What to do
0 to
-9
Low - Slight increase in discomfort - Dress warmly, with the outside temperature in mind.
-10 to
-27
Low - Uncomfortable

- Risk of hypothermia if outside for long periods without adequate protection
- Dress in layers of warm clothing, with an outer layer that is wind-resistant.

- Wear a hat, mittens and scarf.

- Keep active.
-28 to
-39
Increasing risk: exposed skin can freeze in 10 to 30 minutes - Check face and extremities (fingers, toes, ears and nose) for numbness
or whiteness

- Risk of hypothermia if outside for long periods without adequate protection

- Dress in layers of warm clothing, with an outer layer that is wind-resistant.

- Cover exposed skin: wear a hat,
mittens and a scarf, neck tube or face mask.

- Keep active.
-40 to
-47
High risk: exposed skin can freeze in 5 to 10 minutes* - Check face and extremities (fingers, toes, ears and nose) for numbness or whiteness (frostbite)

- Risk of hypothermia if outside for long periods without adequate protection

- Dress in layers of warm clothing, with an outer layer that is wind-resistant.

- Cover all exposed skin: wear a hat, mittens and a scarf, neck tube or face mask.

- Keep active.

WARNING LEVEL**

-48 to
-54
High risk: exposed skin can freeze in 2 to 5 minutes* - Check face and extremities frequently for numbness or whiteness (frostbite)

- Serious risk of hypothermia if outside for long periods
- Be careful. Dress very warmly in layers of clothing, with an outer
layer that is wind-resistant.

- Cover all exposed skin: wear a hat,
mittens and a scarf, neck tube or face mask.

- Be ready to cut short or cancel outdoor activities.

- Keep active.
-55 and colder High risk: exposed skin can freeze in less than 2 minutes DANGER!

- Outdoor conditions are hazardous

- Stay indoors.


Yep, -55 and colder is when it's hazardous. Exposed skin freezes; it just does. The scary thing is, I've been outside on days like that, and it's not that much worse than what I'm about to go into. We're currently at -45, which doesn't even qualify as the "warning level" prior to "hazardous conditions".