Temperature/windchill index: nomogram used by US Air Force at Goose Bay Air Base, Labrador.
Read the temperature horizontally and the wind velocity vertically. The point of intersection is the wind-chill factor. For example, if the wind were 30 km/h and the temperature -25°C, the wind-chill index would be V.
- Comfortable with normal precaution.
- Work and travel become more uncomfortable unless properly clothed.
- Work and travel become more hazardous unless properly clothed. Heavy outer clothing necessary.
- Unprotected skin will freeze with direct exposure over prolonged period. Heavy outer clothing becomes mandatory.
- Unprotected skin can freeze in one minute with direct exposure. Multiple layers of clothing mandatory. Adequate face protection becomes important. Work and travel alone not advisable.
- Adequate face protection becomes mandatory. Work and travel alone prohibited. Supervisors must control exposure times by careful work scheduling.
- Personnel become easily fatigued. Buddy system and observation mandatory.
NOTE: Proper clothing simply means protecting all skin areas from direct wind with sufficient thickness to prevent undue coldness.
Adapted by Duleepa Wijayawardhana, 1998.
Courtesy of McGill-Queen's University Press, Montreal, Quebec. From Hugh M. French and Olav Slamaker, eds.,
Canada's Cold Environments (Montreal: McGill-Queen's University Press, ©1993) 9.