Sauna Sessions Boost Immune Cells, Finnish Study Finds
A Finnish study has revealed that a single sauna session can temporarily increase the number of white blood cells in the bloodstream, which are crucial for the body's immune response. Conducted by researchers at the University of Turku and the University of Eastern Finland, the study involved 51 adults with an average age of 50. Participants experienced a rise in white blood cells, including neutrophils and lymphocytes, after a 30-minute sauna session, followed by a cold shower. These cells returned to normal levels within 30 minutes post-session. The study also noted that cytokine levels, which help coordinate immune activity, varied with body temperature changes during the sauna. The findings, published in the journal Temperature, suggest that sauna bathing may enhance immune surveillance, similar to the effects of physical exercise. 
