Makes sense to me. A lot of bodily fluids sit right on the line between "gel" and "liquid" at room temperature. And gels promote biofilm formation. A few degrees too cool and all your externally-exposed fluids are now gels all the time.
Thus half the reason for saunas (besides the Heat Shock Protein effects): they turn all the gels caught in your pores, your sinuses, your tonsils, your lungs, etc. to liquid, where your body can then much more easily flush them out.
Though, freezing cold air isn't that bad, either: a lot of those liquids will become fully solid. Frozen snot grows no bacteria.
I guess it's just the "danger zone" principle of food safety, applied to human tissue?
Thus half the reason for saunas (besides the Heat Shock Protein effects): they turn all the gels caught in your pores, your sinuses, your tonsils, your lungs, etc. to liquid, where your body can then much more easily flush them out.
Though, freezing cold air isn't that bad, either: a lot of those liquids will become fully solid. Frozen snot grows no bacteria.
I guess it's just the "danger zone" principle of food safety, applied to human tissue?