Overview
Passive body heating in the evening — a sauna session, a hot bath, a warm shower — is followed by a rebound drop in core temperature. A meta-analysis of warm baths and showers timed one to two hours before bed found faster sleep onset. The sauna version applies the same mechanism with more heat and more caution: finish early enough that the rebound happens before lights out, keep the session moderate, and rehydrate. Timed too late, the residual heat works against you.
Evidence level
Supported. Useful evidence exists, but outcomes or dosing vary. How Compound evaluates evidence
Sources
