A single sauna session sends immune cells surging through your body

A new Finnish study reveals that just 30 minutes in a sauna can temporarily flood the bloodstream with additional white blood cells, potentially helping the immune system patrol the body and detect threats. The surprising response resembles the immune boost seen during exercise and may help explain some of the health benefits linked to sauna bathing. A single sauna session may trigger a surprising response in the immune system. Researchers in Finland have discovered that spending just 30 minutes in a sauna, with a brief cold shower halfway through, causes white blood cells to surge into the bloodstream. These cells are essential to the body's defenses, helping identify and fight infections and other potential threats.

The findings suggest that sauna bathing may temporarily mobilize immune cells that normally remain in tissues, allowing them to circulate more widely throughout the body. This increased movement could help the immune system monitor for harmful pathogens, including bacteria and viruses. During the study, researchers observed an increase in every type of circulating white blood cell they measured. Among them were neutrophils and lymphocytes, two important groups of immune cells. Neutrophils are often among the first defenders to respond to an infection, while lymphocytes include cells that recognize specific threats,