When the forecast says “minus 15, feeling like minus 28,” that second number is the wind chill. It’s not a different temperature. It’s a measure of how fast the wind pulls heat away from your skin.
On a calm day, your body keeps a thin layer of warm air right next to your skin. Wind strips that layer away as fast as you can make it. That’s why a −15°C day with a stiff west wind can be far more dangerous than a still −25°C morning.
How fast frostbite can happen
Environment and Climate Change Canada uses these guidelines for exposed skin:
- Wind chill of −28 to −39: frostbite possible in 10 to 30 minutes
- Wind chill of −40 to −47: frostbite possible in 5 to 10 minutes
- Wind chill of −48 to −54: frostbite possible in 2 to 5 minutes
- Wind chill of −55 or colder: frostbite possible in under 2 minutes
What to do
- Cover your face, ears and fingers first. Those are where frostbite starts.
- Dress in layers, with a windproof outer layer. Wind goes right through wool and fleece.
- Take warm-up breaks if you’re working outside.
- Watch kids, older family members and pets. They lose heat faster.
- Keep a blanket, hat and gloves in the vehicle in case you get stuck.
Early signs of frostbite are white or greyish-yellow skin that feels numb or waxy. Warm the area gently and get medical help if the skin doesn’t return to normal.
See the current wind chill for West Lethbridge at westlethbridgeweather.com, and our First Aid page covers cold injuries in more detail.
Related: Live conditions at West Lethbridge Weather · First Aid