Does Sauna actually make a difference, or is it overhyped?

A well-known Finnish cohort study (KIHD) found frequent sauna bathing (4-7 times per week) was associated with substantially lower fatal cardiovascular and all-cause mortality compared with once weekly, a finding extended by related analyses from the same cohort linking sauna use, cardiorespiratory fitness, and reduced risk of sudden cardiac death. Weighing the data: Sauna looks potentially significant but still under-researched — its estimated impact on longevity is rated high (62/100), while the evidence itself is only moderate (72/100).