As Europe heats up, study finds heat training boosts concentration in extreme temperatures

Researchers found that a week-long heat-training programme improved attention by around 10 per cent during exercise in 40°C conditions, while also reducing feelings of mental effort and fatigue – offering new insights into how people can adapt quickly to increasingly hot conditions.

The findings come against a backdrop of increasingly extreme temperatures across Europe. The continent has warmed at more than twice the global average rate over the past 30 years, according to the Copernicus Climate Change Service. This spring saw temperatures in the UK climb above 35°C in May for the first time on record, while several European countries experienced unusually early extreme heat.

Against this backdrop, the Met Office has warned that June temperatures could be among the highest on record in parts of the UK, highlighting the growing need to understand how people can safely adapt to exercising and working in extreme heat.

Environmental Extremes Lab

The international study was led by Thomas Goepp, a PhD researcher based at the University of Brighton and LIBM University Savoie Mont-Blanc in France. He worked with colleagues from Brunel University London and University Savoie Mont-Blanc, with University of Brighton researcher Mark Hayes serving as corresponding author.

Published in the Scandinavian Journal of Medicine & Science in Sports, the research explored whether heat acclimation – a process in which repeated exposure to heat helps the body adapt to hot conditions – could improve both physical and cognitive performance during exercise in extreme temperatures.

To test this, researchers recruited 20 endurance-trained adults, most of whom were runners, cyclists or triathletes, and asked them to complete a demanding dual task in a chamber set at 40°C. Participants cycled at an intense pace, while simultaneously undertaking an attention test designed to assess their ability to stay focused under pressure.

Following six heat-training sessions completed over approximately one week, participants performed significantly better on the attention task during exercise in the heat and reported lower levels of mental strain. The findings suggest that adapting to heat may help preserve not only physical performance but also concentration and decision-making when conditions become challenging.

The researchers say the findings could have implications for athletes, military personnel, emergency responders and outdoor workers, many of whom are increasingly required to perform complex tasks in hot environments.

Perhaps most surprisingly, the researchers found that participants could achieve similar benefits from heat training while exercising less intensely.

Those using blood-flow restriction training – a technique that temporarily reduces blood flow to the muscles during exercise – showed similar improvements in their ability to cope with hot conditions and experienced less fatigue, despite completing their training at lower workloads.

The findings raise the possibility of making heat training more accessible for people who may be unable to tolerate higher training loads, including injured athletes, older adults, people recovering from illness or surgery, and those returning to exercise after a break.

Mark Hayes, researcher in the Environmental Extremes Laboratory at the University of Brighton and corresponding author of the study, said: "When we talk about the risks of extreme heat, the focus is often on physical health. But heat can also affect our ability to concentrate, make decisions and perform everyday tasks safely and effectively.

"As temperatures continue to rise, understanding how people can adapt to these conditions is becoming increasingly important. Our findings suggest that even a relatively short period of heat training can help people better cope with the combined mental and physical demands of hot environments."

Thomas Goepp added: "What was particularly encouraging was that we saw improvements in attention after just one week of heat training. Participants were better able to maintain focus while exercising in conditions that would be challenging for most people.

"This suggests that adapting to heat is not only about improving physical tolerance. It may also help preserve mental performance when people need to stay alert, focused and make decisions under pressure."

While the study focused on trained adults, the findings suggest that a short period of heat training can help people stay focused during demanding activity in extreme temperatures. The researchers also found that similar benefits could be achieved using blood-flow restriction training, despite participants exercising at lower workloads and experiencing less fatigue.

This may be particularly important for athletes, military personnel and workers who regularly face physically and mentally demanding tasks in the heat. As Europe experiences more frequent and intense heatwaves, the research could help inform future approaches to heat preparedness, although the researchers caution that further work is needed before the findings can be translated into advice for the wider public.

The research forms part of a wider programme of work taking place in the University of Brighton's Environmental Extremes Laboratory, which explores how people respond and adapt to environmental stressors including heat, cold and altitude.

Using specialist environmental chambers capable of recreating extreme conditions, researchers are investigating practical strategies to help people live, work and exercise safely as temperatures continue to rise.

The research was supported through doctoral research funded by the Agence Innovation Défense, part of the French Ministry of Defence.