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With climate change increasing seasonal temperatures and causing more frequent heatwaves, understanding these effects has become more crucial than ever.
Hormones play a role in nearly all biological functions, yet the influence of environmental factors on hormone release and action is not well characterised. Researchers from the University of Oxford, the London School of Hygiene & Tropical Medicine, the William Harvey Research Institute at Queen Mary University of London, and the National University of Singapore have highlighted the urgent need for more research into the effects of heat exposure, particularly in the context of climate change increasing seasonal temperatures and causing more heatwaves.
Hormones influence how we adapt to changes in environmental temperature by controlling processes such as conservation of body water, sweating, and heat generation from cell metabolism. A review of studies published from the 1940s onwards indicates that heat exposure affects hormones involved in processes ranging from the stress response, blood glucose control, fertility, and breast milk production. However, many of these studies involved short-term heat exposure in non-human animal models or in healthy human volunteers such as military recruits.
Our review highlights the gap in evidence regarding the impact of sustained heat exposure on the endocrine system, which is particularly relevant to the increasing numbers of people living with endocrine conditions such as diabetes mellitus or thyroid disorders, who may have limited tolerance to higher temperatures. Heatwaves increase the risk of hospitalisation for these patients, which also increases the burden of heat on the health system.