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by the NFCC


Physiological stress

Hazard Knowledge

Physiological stress is the body’s response to a stressor, such as an environmental condition or a stimulus. Examples of physiological stress are fatigue, dehydration, heat illness and hypothermia.

Fatigue is a subjective feeling of tiredness which has a gradual onset; it can have physical or mental causes and may significantly affect a person’s ability to perform tasks.

Dehydration occurs when the body loses more fluid than it takes in; minerals in the body become unbalanced, which affects the way that it functions.

The ability of personnel to operate effectively may be affected by physiological stress. This could be caused by:

  • The environment and weather conditions
  • The task they are undertaking
  • Their personal protective equipment
  • Their condition prior to being mobilised, including illness and physical condition