carbonic acid shifts skin temperature receptors, making cooler water feel comfortably warm
CO2 baths inhibit cold receptors and stimulate warmth receptors in the skin, lowering the thermoneutral temperature from approximately 35°C (fresh water) to 32–33°C (CO2 water).
What this means for you
Your skin's cold and warmth receptors respond differently in CO2-rich water — cooler temperatures feel neutral or pleasant instead of chilly. For most people this means a deeply relaxing, comfortable experience even at lower water temperatures, which may support circulation and recovery without the stress of heat.
The published research
Carbon Dioxide Bath (Carbon Dioxide Spring)
This page describes a documented finding about the underlying wellness technology. It is not a marketing claim about any specific device. For information about HOCATT specifically, visit hocatt.com.