Exertional heat illness
Meaning of exertional heat illness: For the purposes of this Statement of Principles, exertional heat illness: (a) means an illness caused by an increase in body temperature that exceeds the body's ability to lose heat, due to exposure to physical activity in a setting of high environmental temperatures; and (b) includes: (i) heat exhaustion (also known as heat fatigue, heat intolerance and heat stress); (ii) heat injury; (iii) heat stroke; and (iv) heat syncope; and (c) excludes: (i) drug hypersensitivity reactions; (ii) exertional hyponatraemia; (iii) isolated exertional rhabdomyolysis (without evidence of heat-related illness); (iv) malignant hyperthermia associated with anaesthetic agents; (v) neuroleptic malignant syndrome; (vi) pyrogenic hyperthermia; and (vii) serotonin syndrome.
Reasonable Hypothesis (RH) — Statement of Principles No. 31 of 2022
At least one of the following factors must as a minimum exist before it can be said that a reasonable hypothesis has been raised connecting exertional heat illness or death from exertional heat illness with the circumstances of a person's relevant service:
- (1)undertaking physical activity at a minimum intensity of at least 3 METs in a hot environment at the time of the clinical onset of exertional heat illness;
Note: Exertional heat illness generally occurs at higher levels of physical activity and environmental heat. The likelihood of developing exertional heat illness can be increased in milder environmental temperatures in the presence of other contributing factors. These include prolonged activity, high humidity, lack of breezes, wearing heavy protective clothing or combat clothing, carrying heavy loads, poor physical fitness, lack of acclimatisation, being overweight or obese, and taking drugs which affect thermoregulation.
Note: MET is defined in the Schedule 1 - Dictionary.
- (2)inability to obtain appropriate clinical management for exertional heat illness;
Aggravation-only factors: the factors in subsection 8(2) apply only to material contribution to, or aggravation of, the condition where it was suffered or contracted before or during (but did not arise out of) the person’s relevant service.
Balance of Probabilities (BoP) — Statement of Principles No. 32 of 2022
2 factors
At least one of the following factors must exist before it can be said that, on the balance of probabilities, exertional heat illness or death from exertional heat illness is connected with the circumstances of a person's relevant service:
- (1)undertaking physical activity at a minimum intensity of at least 3 METs in a hot environment at the time of the clinical onset of exertional heat illness;
Note: Exertional heat illness generally occurs at higher levels of physical activity and environmental heat. The likelihood of developing exertional heat illness can be increased in milder environmental temperatures in the presence of other contributing factors. These include prolonged activity, high humidity, lack of breezes, wearing heavy protective clothing or combat clothing, carrying heavy loads, poor physical fitness, lack of acclimatisation, being overweight or obese, and taking drugs which affect thermoregulation.
Note: MET is defined in the Schedule 1 - Dictionary.
- (2)inability to obtain appropriate clinical management for exertional heat illness;
Aggravation-only factors: the factors in subsection 8(2) apply only to material contribution to, or aggravation of, the condition where it was suffered or contracted before or during (but did not arise out of) the person’s relevant service.
