Hot Water Immersion Triggers Stronger Heat and Immune Response Than Saunas
In a controlled study, 20 healthy young adults were exposed to hot water immersion, traditional sauna, and far‑infrared sauna. All methods raised core temperature, but hot water immersion produced the highest core temperature and strongest cardiovascular responses (heart rate, blood flow, cardiac output) and elicited measurable inflammatory immune changes, likely because sweating is less effective in water. The findings highlight that heat delivery matters for physiological stress and suggest heat therapy could aid those unable to exercise, but long-term benefits aren’t established and medical clearance is advised for people with heart conditions; heat therapy is not a substitute for regular exercise.
