30-minute sauna session temporarily boosts immune cell circulation

Researchers in Finland discovered that spending 30 minutes in a sauna, including a brief cold shower, causes a temporary surge of white blood cells in the bloodstream, according to ScienceDaily Health.

The study observed increases in all types of circulating white blood cells measured, including neutrophils and lymphocytes, which play key roles in identifying and fighting infections.

This immune cell increase is temporary, with counts returning to baseline within 30 minutes after the sauna session.

The researchers suggest that sauna bathing mobilizes white blood cells from tissues into the bloodstream, allowing them to patrol the body more effectively, a process known as immune surveillance.