Does sauna increase blood glucose?

Sauna use can indeed increase blood glucose levels, which Andrew Huberman discovered and was surprised to learn. He explained that going into a sauna caused his blood glucose to spike as high as it would after a meal. This spike is due to dehydration, which occurs when you sweat heavily in the sauna and don't drink water, leading to a higher concentration of sugar in your blood. The blood glucose typically falls back to baseline or even slightly below after some time post-sauna session. Despite this effect, Dr. Huberman continues to use the sauna because of its significant psychological and physical health benefits and accepts these temporary increases in blood glucose levels 1.