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About this tool
Wind chill, frostbite exposure time and a layer-by-layer kit list for training in the cold at your planned intensity.
The Cold Weather Workout Layering Guide turns the temperature, wind speed and your planned session into a specific kit list. It calculates the 2001 North American wind chill index used by the US National Weather Service and Environment Canada, adds the warmth your own effort generates using the classic coaching rule of dressing for 10 to 20 °F warmer than it is, then names a layer for the head, torso, hands, legs and feet — along with the frostbite exposure time for uncovered skin.
Open Cold Weather Workout Layering Guide on AltFTool — it loads instantly in your browser.
Add your input to the workspace.
Adjust the options until the result looks right.
Copy or download the output and put it to work.
The official NWS and Environment Canada formula, applied only inside its valid range.
Hard sessions shift the dressing temperature up to 11 °C warmer than the thermometer reads.
Head, torso, hands, legs and feet each get a specific layer instead of vague advice.
The 2001 North American index is WCI = 13.12 + 0.6215 T − 11.37 V^0.16 + 0.3965 T V^0.16, with T in degrees Celsius and V the wind speed in km/h. It is only defined for temperatures at or below 10 °C with wind above 4.8 km/h — outside that range the air temperature is what you should use.
Environment Canada puts frostbite risk for exposed skin at 10 to 30 minutes once the wind chill reaches −28 °C, 5 to 10 minutes below −40 °C, and under 2 minutes below −55 °C. Below about −28 °C nothing should be uncovered, and at −48 °C or colder the sensible call is to move the session indoors.
Because working muscle produces a large amount of heat, and clothing that feels right standing still leaves you soaked in sweat ten minutes in — which then chills you when you stop. The long-standing coaching rule is to dress for 10 to 20 °F (roughly 5 to 11 °C) warmer than the reading, with the bigger allowance for harder efforts. You should feel slightly cold for the first five minutes.
Cold dry air is one of the best-recognised triggers for exercise-induced bronchoconstriction, because rapid breathing dries and cools the airway lining. Breathing through a buff or scarf pre-warms and humidifies the air, and a longer gradual warm-up reduces the response. If you have been prescribed a reliever to use before exercise, follow your clinician's instructions rather than this guide.