Introduction to Cold Weather Effects
We hear the amazing survival story of a child trapped under the ice of a frozen lake for one hour. A skier, lost and found in sub-zero temperatures, miraculously recovered in hospital after several hours of rewarming his frost-bitten body. Both were lucky? Probably. Despite the partly frozen condition of their ‘shell’ (skin, outer layers of fat and muscles), their core body temperatures were high enough to allow the survival of their essential organs. Most aren’t so lucky: many soldiers who suffered from cold exposure during war have been left with body scars, or even developed painful symptoms decades later.
Human health is not the only casualty of cold weather, as wild, farm and domestic animals also suffer greatly. Newborn lambs and calves often don’t survive an unseasonably cold outbreak. Some crops succumb to spring frosts, while fruit trees shed their flowers before they set fruit, leaving the farmer with a reduced or zero income. Substances expand in heat and contract in cold. The contractions of metal and concrete may become so severe that buildings suffer permanent damage. Your car suffers, too. The battery goes flat or the engine cracks if you push it too hard. Cold weather is the time to turn up the heater at home and at work. On such days, the energy consumption reaches peaks equally as high as during heat waves. The demand can be too high and blackouts occur.
Vostok Station on Antarctica recorded the lowest temperature on Earth, –89°C. Obviously, exposure to such low temperatures is dangerous and explorers take appropriate precautions. Less dangerous, but of a much higher impact on the population’s health, are the cold, wet and windy conditions of the temperate regions.
The body is under cold stress when the temperature diverges excessively from the average. Melbourne, Australia is considered to have a temperate climate. Nevertheless, the temperatures can range from the highest recorded 45.6°C in summer to the lowest recorded of –2.8°C in winter. The US town of Warsaw, Missouri recorded extremes of 47.8°C as the highest and –40.0°C as the lowest.
The Wind Chill Factor
A breeze is very welcome in summer. The wind replaces the hot and humid air near your skin with cooler and drier air. More sweat can evaporate and cool your body. In winter you don’t want this effect. You want the air near your skin to stay and provide a thin layer of insulation. In winter it is very important to wear clothes that limit the exchange of air near your skin – unless it is desired during exercise or outdoor work. A stormy winter’s day, however, may penetrate whatever you are wearing and you will feel much colder than the actual air temperature around you.
Scientists incorporated the ‘feel’ factor into a wind chill index. For example, a measured temperature of 0ºC feels like –16ºC when a 37km/h wind blows.