Just a note on the study - the technique we validated evaluates the upper limit for thermoregulation, above which core temperature will increase to dangerous levels over a relatively short period.

The thresholds are much higher than those for discomfort and (likely) impacts on focus, learning etc.

Let me know if you have any Qs 😁

For all intents and purposes, human skin has a max temperature of ~35C. Since sweat evaporation is our primary mode of heat loss, a wet bulb temp of 35C - equivalent to 35C air temp with 100% humidity - means that there is no vapour pressure gradient for skin-environ evaporation and thus no cooling

Understanding how thermoregulation differs between these areas and those experiencing the greatest increases in humid heat is critical for future heat warnings and adaptation planning.

Looking into the future, there is a need to evaluate upper limits in a wider range of populations, as thermal step protocols have been employed primarily in laboratories from temperate areas.

Thermal step protocols are an effective and efficient method for estimating upper limits for thermoregulation. This is great news, as they are widely used and being increasingly incorporated into large scale #climate #modelling.

We exposed young adults for 9 hours to conditions just above or below the core temperature inflection point and found that thermal step protocols work extremely well.

However, despite being around for over 50 years, thermal step protocols have never been validated.

There are increasing concerns that #heatwaves of the future will be so hot and humid that they exceed the limits of human heat tolerance. Recent laboratory research using “thermal-step protocols” has argued that these limits are likely lower than once thought.

Only on Canadians! The purpose of the study was to validate the technique used to assess upper limits for thermoregulation. Turns out that technique works quite well, but you are absolutely right that there is a need to expand research to a wider range of populations/contexts (which we discuss)