Cold water immersion has gone from a niche recovery technique used by elite athletes to something you will find in gyms, wellness centres, spas, hotels, and holiday parks across the UK. If you manage a facility that has added (or is thinking about adding) a cold plunge pool or ice bath, the compliance picture is different from a standard swimming pool and it is worth understanding before you get caught out.
I manage cold plunge pools at a sports facility, so this is something I deal with every day. The guidance has been evolving quickly, and 2025 saw some important developments that every commercial operator should be aware of.
The regulatory picture
Just like standard swimming pools, there is no specific UK legislation that regulates cold plunge pools directly. The same general framework applies: the Health and Safety at Work Act 1974, the Management of Health and Safety at Work Regulations 1999, and HSG179 as the benchmark guidance for pool safety management.
What has changed recently is that the industry bodies have started producing specific guidance for cold water immersion. PWTAG published Technical Note 71, which deals specifically with ice baths in commercial settings. And BISHTA and SPATA have jointly developed cold water immersion guidance that aligns with HSG282 and PWTAG recommendations for commercial operators like gyms, wellness centres, spas, and holiday parks.
This matters because if an EHO visits your facility and asks about your cold plunge compliance, they will now have specific guidance to measure you against rather than just the general swimming pool standards.
How cold plunge pools differ from standard pools
The fundamental difference is temperature, and temperature changes everything about how you manage the water.
Reduced microbiological risk at low temperatures: Cold water (typically 8 to 15 degrees) significantly reduces the rate at which most bacteria and microorganisms grow. This is good news from a hygiene perspective, but it does not eliminate the need for disinfection entirely. You still need a sanitiser in the water if it is being retained between users.
Different chlorine behaviour: Chlorine behaves differently in cold water compared to a pool at 28 to 30 degrees. The disinfection chemistry still works, but the rates of reaction change. Your parameter ranges need to reflect the actual water temperature, not just the standard pool ranges.
Higher bather-to-volume ratio: Cold plunge pools are typically much smaller than swimming pools, but can see a high throughput of users. A small plunge pool used by 20 people in a morning session has a very different contamination profile to a 25-metre pool with the same number of swimmers.
Different user behaviour: People using cold plunge pools are typically immersing for short periods (2 to 10 minutes), often moving between hot and cold (contrast therapy). They are sweating heavily if they have just been in a sauna or steam room. This introduces contaminants into a small volume of water very quickly.
Water quality requirements
The core testing requirements still apply to cold plunge pools, but with some adjustments for the temperature and usage profile.
Free chlorine: You still need adequate disinfection. The exact level will depend on your setup, but the principle is the same as any other pool: enough free chlorine to maintain a safe residual, tested regularly throughout the operating day.
pH: The same 7.2 to 7.4 range applies. pH control is just as important in cold water because it determines how effective your chlorine is.
Combined chlorine: Should still be below 1.0 mg/L and less than half of your free chlorine reading.
Temperature: Obviously this is different from a standard pool. Record the water temperature at every test. Your target range will depend on what the pool is used for, but most cold plunge pools operate between 8 and 15 degrees. Some ice bath setups go colder.
Microbiological sampling: Monthly sampling still applies. The lower temperature reduces bacterial growth, but contamination from bathers (particularly in a small volume with high turnover) still needs monitoring. If your cold plunge pool is used as part of a hydrotherapy or rehabilitation programme, weekly sampling may be more appropriate.
Operational considerations
Fill and empty versus continuous treatment
Some cold plunge pools, particularly smaller ice bath style setups, are designed to be emptied and refilled regularly (sometimes after every user or every session). If you are operating on a fill-and-empty basis, your compliance requirements are different from a continuously treated pool.
If the water is emptied after each use, BISHTA guidance suggests there may be no need for a sanitiser in the water itself, but the tub surfaces still need proper cleaning with an appropriately tested product between fills. If the water is retained for multiple users, you need active disinfection and the full testing regime applies.
Most commercial facilities with built-in plunge pools run continuous treatment systems because the volume of water and the frequency of use makes fill-and-empty impractical.
Supervision and safety
Cold water immersion carries specific health risks that standard swimming does not. The cold shock response can cause involuntary gasping, hyperventilation, and in extreme cases cardiac events. BISHTA guidance is clear that cold plunge pools should not be used unsupervised, particularly at temperatures below 10 degrees.
Your NOP and EAP (as required by HSG179) need to specifically cover cold water immersion scenarios. What happens if someone has a cold shock response? What are the signs? What is your response procedure? Staff need to understand these risks and be trained to respond.
Additional safety measures to consider: non-slip surfaces around the pool, handrails or grab bars for entry and exit, clear signage about recommended immersion times and contraindications (heart conditions, pregnancy, Raynaud's disease), and a maximum immersion time policy.
User screening
Unlike a standard swimming pool where anyone can walk up and get in, cold plunge pools should have some form of user screening. At minimum, signage warning about contraindications. Ideally, a brief verbal check or questionnaire for first-time users. BISHTA recommends that children under 16 should not use cold tubs unless under appropriate medical supervision.
This user screening should be documented in your PSOP and your staff should understand why it matters.
Record keeping
The same record-keeping requirements apply as for any other commercial pool. Every water test needs to be logged with date, time, operator, and all parameter values. Out-of-range readings need documented corrective actions. Microbiological lab results need to be filed and accessible.
The challenge with cold plunge pools is that they are often managed as an afterthought, bolted onto the side of a gym or spa operation where the main focus is on the swimming pool or hydrotherapy suite. The plunge pool testing gets done last, or gets skipped when things are busy. This is exactly the kind of gap an EHO will spot.
If you are managing multiple pools including cold plunge facilities, having all your records in one system rather than scattered across different log books makes a significant difference to your ability to demonstrate consistent compliance.
What is coming next
The cold water immersion market is growing fast, and the guidance is still catching up. PWTAG Technical Note 71 and the BISHTA/SPATA guidance are the first formal industry standards, but they will almost certainly be refined as more commercial operators enter the space and more data becomes available.
If you are installing or already operating a cold plunge pool, the smart move is to get ahead of the guidance rather than waiting for it to catch up with you. Apply the same compliance discipline you would to any other pool: test regularly, record everything, maintain your equipment, and train your staff.
How AquaAssure handles cold plunge pools
AquaAssure supports multiple pools with different parameter ranges within the same facility. Your cold plunge pool can have its own temperature range (8 to 12 degrees rather than 28 to 30), its own testing schedule, and its own compliance thresholds, all sitting alongside your main pool and hydrotherapy suite in the same dashboard.
When an operator logs a reading for the cold plunge, the system checks it against the correct ranges for that specific pool, not the generic swimming pool standards. This is exactly the kind of detail that matters when you are managing several different types of pool from one plant room.
If you want to see how this works in practice, book a demo. We manage cold plunge pools alongside hydrotherapy and swimming pools every day, so we can show you a real setup rather than a theoretical one.