Infectious Disease A Sauna Floods Your Blood With Immune Cells. It's a Flush, Not a Boost.
Fifty-one Finns sat in a 73°C sauna for half an hour, and every white blood cell type poured into their blood. Half an hour later the neutrophils and lymphocytes were back to baseline, and the immune system's chemical alarm had barely rung.
By Sarah Okonkwo · August 13, 2026