California bill would regulate cold plunge tubs and cold spas

Cold plunges are moving out of the wellness free-for-all and into California’s public-health rulebook. AB 2330 would create a separate legal framework for cold spas and cold plunge tubs, a shift that could mean safer access for users, but also new compliance costs for operators and gym owners.

The bill was introduced by Assembly Member Tasha Boerner on February 19, 2026, amended on April 6 and April 16, and was held under submission in committee on May 14. The legislative digest says it would add Article 5.5 to the Health and Safety Code, and committee materials frame it as a public health response to the rise of cold-water recovery facilities. That matters because California already regulates public swimming pools and spa pools under existing law, but lawmakers are now drawing a line between ordinary aquatic amenities and immersion setups built for short, icy sessions.

Under the analysis, a cold spa would be an in-ground public swimming pool used for brief therapeutic or recovery immersion, kept between 35 and 60 degrees Fahrenheit with a mechanical chiller or another approved cooling method. It would be built for multiple users at once and would need a mechanical recirculation system that continuously or intermittently circulates, filters, and disinfects water. A cold plunge tub would be different: an aboveground, individual-use therapeutic tub in the same temperature range, with mechanical recirculation and automatic disinfection using chlorine or bromine, plus optional ozone or UV secondary treatment.

The bill would also require cold plunge tubs to be drained at the end of each operating day and refilled at the start of the next, and it would bar them from being placed or used in the same enclosure as a public pool or spa. Just as notably, operators would have to post signage saying the tub is not regulated as a public swimming pool and that users are taking the risk themselves. San Francisco Department of Public Health already treats cold plunges as a distinct category in practice, defining them as single-occupant, stand-alone, prefabricated, aboveground cold-water tubs for therapeutic use, typically below 59 degrees.

For operators, builders, and gyms, the likely effect is both safer access and higher costs. Clearer rules could improve sanitation, reduce confusion, and make it easier to open or inspect a facility, but they could also force changes in design, permitting, liability planning, and maintenance. The National Collaborating Centre for Environmental Health has noted that cold temperatures may reduce disinfectant effectiveness, which helps explain why lawmakers are no longer treating the plunge tub like a trendy add-on. They are treating it like infrastructure.