Heat acclimation protocol shows promise for older adults during heatwaves

University of Ottawa researchers observed physiological adaptations in older adults after a 7-day hot water immersion protocol, with potential implications for reducing heat-related mortality risks.

A University of Ottawa study tested heat acclimation in older adults through a 7-day protocol involving 2 hours of daily immersion in 40°C water. Participants aged 60-80 showed physiological adaptations including earlier and more intense sweating, enhanced skin blood vessel dilation, and reduced heart rate over time. Blood samples from men aged 60-70 revealed increased heat shock protein concentrations, which stabilize cellular proteins damaged by heat. The research builds on observed European heat wave mortality estimates of over 10,000 deaths in June 2023, highlighting urgent need for protective strategies for vulnerable populations.

The findings suggest that controlled heat exposure could trigger cellular resilience mechanisms. Heat shock proteins act as cellular repair systems during thermal stress, potentially mitigating damage that contributes to heat-related illness. This protocol offers a pathway to build tolerance without extreme environmental exposure, addressing a critical gap in heat protection for aging communities.

The results are limited to a small group of healthy adults aged 60-80, with heat shock protein findings specifically from men. Hypothalamic heat response mechanisms described in the study are based on mouse research requiring further human validation. Population-level adaptation thresholds (like the UK’s minimum mortality temperature range) remain interpretations rather than direct measurements. Future work must confirm whether similar adaptations occur across diverse age groups and genders to scale this approach for broader heatwave resilience.

Source: Science News