Hot Bath

Hot water immersion ranks first in physiological stress among the three heat immersion methods. Hot water immersion generates the highest heart rate increase of the three heat immersion methods. Hot water immersion produces the greatest sweat loss among the three heat immersion methods. The recommended protocol is 40°C (104°F) water temperature for 30 minutes. The benefits described are specific to the 40°C temperature range, not just any warm soak. Hot water immersion produces the largest increase in core body temperature of the three methods. Several additives enhance the effects of a hot bath. Heat redirects blood flow into peripheral muscles and skin, which can cause orthostatic dizziness when standing.