Environmental factors affecting heat ageing

Age, weight, degree of physical fitness, degree of acclimatization, metabolism, use of alcohol or drugs, and a variety of medical conditions, such as hypertension, all affect a person s sensitivity to heat. However, even the type of clothing worn must be considered. Prior heat injury predisposes an individual to additional injury. It is difficult to predict just who will be affected and when, because individual susceptibility varies. In addition, environmental factors include more than the ambient air temperature. Radiant heat, air movement, conduction, and relative humidity all affect an individual s response to heat. 

Numerous tests and studies have been conducted to investigate and determine how these properties are affected by environmental and other factors such as aging, temperature, heating, history of loading, etc., and modification factors for these properties have been proposed... 

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