A 2022 study experimentally found the limit to be 30.5C ± 1C at 100% humidity, and lower in dry environments. https://journals.physiology.org/doi/full/10.1152/

A 2022 study experimentally found the limit to be 30.5C ± 1C at 100% humidity, and lower in dry environments. https://journals.physiology.org/doi/full/10.1152/japplphysiol.00738.2021 https://journals.physiology.org/doi/full/10.1152/japplphysio...