There are regions in the world where low ambient temperatures hinder or prevent undertaking of normal physical tasks. Skilled jobs requiring manual dexterity are difficult. The likelihood of errors or accidents increases, particularly when the temperature of the hand falls below 15 deg. C. At 51 deg. C, metal becomes as brittle as glass, camera film snaps and rubber soles of shoes break.
Outdoor jobs in cold climates are found not only at high latitudes but also in temperate zones at high altitudes and in winter. Those at risk in the temperate zones are all outdoor workers exposed to environmental temperatures below about 10 deg C, especially when wind and rain supervene.