From the Guidelines
Stress can indeed induce hyperthermia in the body, as it triggers the release of stress hormones such as cortisol and adrenaline, leading to an increase in metabolic rate and enhanced thermogenesis 1.
Key Mechanisms
- The activation of the hypothalamic-pituitary-adrenal (HPA) axis plays a crucial role in this process, as it stimulates the release of stress hormones 1.
- These hormones can increase metabolic rate, leading to enhanced thermogenesis and a subsequent rise in core body temperature.
Management of Hyperthermia
- In extreme cases, chronic stress may necessitate intervention with anxiolytic medications like alprazolam (0.5-2mg, orally, twice daily) or beta blockers like propranolol (20-40mg, orally, twice daily) to mitigate the physiological effects of stress, including heat production.
- Management of hyperthermia often involves terminating the extreme muscle activity, and benzodiazepines may be useful in controlling muscular activity in moderate cases 2.
Important Considerations
- The notion that stress can be acclimatized to minimize its impact on the cardiovascular system is doubtful, as even 10 days of conditioning can fail to prevent the large changes in BP and heart rate induced by restraint stress 1.
- The accuracy of indirect BP measurement methods in animals, particularly tail-cuff methods, is open to question, and may not accurately reflect the true effects of stress on the body 1.
From the Research
Stress and Hyperthermia
- Stress can activate the hypothalamic-pituitary-adrenal (HPA) axis, leading to the release of hormones such as cortisol and adrenaline 3
- These hormones can stimulate thermogenesis, which is the production of heat in the body, potentially leading to hyperthermia 3
- The relationship between stress and hyperthermia is complex, and other factors such as fitness level and environmental conditions can also play a role 4
Physiological Responses to Heat Stress
- The human body responds to heat stress by initiating cutaneous vasodilation and eccrine sweating to facilitate heat loss 5
- The autonomic nervous system plays a crucial role in regulating body temperature during heat stress, and the cumulative imbalance between heat production and heat dissipation can lead to body heat storage and hyperthermia 5
- The biophysical aspects of human thermoregulation, including the properties of the skin and the environment, can influence the body's ability to regulate temperature during heat stress 5
Hyperthermia and Heat Stress
- Hyperthermia can occur when the body's heat production exceeds its ability to lose heat, and this can be exacerbated by factors such as dehydration and humidity 6, 7
- Exercise under heat stress can disrupt thermoregulation and fluid balance, leading to hyperthermia, hypohydration, and exertional heat illness 7
- Strategies such as heat acclimation, cooling, and hyperhydration can help mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat 7