This is an excerpt from ACSM's Health/Fitness Facility Standards and Guidelines 4th Edition eBook by American College of Sports Medicine.
Saunas, steam rooms, and whirlpools are all potentially high-risk areas to members and users because of the high temperatures and humidity that are generated in these spaces. A facility's failure to maintain these three areas at what are considered safe temperature and humidity levels can further expose members and users to harmful conditions, such as hyperthermia, heat exhaustion, heatstroke, and cardiovascular emergencies. Even when maintained at the proper temperature, these three areas can still result in dangerous consequences if individuals are not warned of the associated risks and precautions that go with their use. While events such as heart attack and stroke are very rare, events such as orthostatic syncope (i.e., a condition where a person feels dizzy or faint from the venous pooling of blood that occurs upon changing from a supine to upright position) or heat exhaustion and heatstroke have a higher likelihood of occurring. Table 5.2 provides an overview of the recommended temperature ranges and precautions for saunas, steam rooms, and whirlpool areas.
In most states, either the state or local municipality with governing authority establishes standards for the proper water chemistry. Most state and local codes provide minimums for the various chemical levels of the water. Facility operators can also refer to the National Spa and Pool Institute (NSPI) for more thorough information on the proper water chemistry for pools and whirlpools (spas). Table 5.3 provides an overview of the ranges recommended by the NSPI for the most critical water chemical levels in a pool.
Read more from ACSM's Health/Fitness Facility Standards and Guidelines-4th Edition by American College of Sports Medicine.