Hot Tubs May Be Better Than Saunas for Heart and Immunity.

A 2025 study from the University of Oregon’s Bowerman Sports Science Center compared hot tubs, traditional saunas, and infrared saunas in 20 healthy adults (20–28 years old). Soaking in a hot tub raised core temperature the most, triggering stronger cardiovascular and immune responses—like increased heart output, improved blood flow, lower blood pressure, and boosted white blood cells—compared to saunas.

The deeper heat from hot water immersion likely kept the body warmer longer than dry saunas, which cool more quickly via sweat evaporation. That prolonged heat stress led to beneficial effects that mimic mild exercise—such as better vascular function and immune readiness.

For heart health, blood pressure support, and immune boost, try adding a regular 20–30 minute hot tub soak into your wellness routine.