The buoyancy of water reduces pressure on joints and muscles, especially in the shoulders, neck, and lower back. Muscle tension is a common physiological manifestation of anxiety. The buoyancy of a spa hot tub relaxes muscles, reducing body pressure and thus lowering psychological anxiety.

Soaking in a spa hot tub for more than 15 minutes causes the hot water to dissolve the skin's lipid barrier, weakening its natural moisturizing barrier. The result is that while the skin feels moist for a short time after soaking, the moisture evaporates quickly, leaving a tight and dry feeling.

Studies show that bacteria multiply fastest in water temperatures between 35–42°C, which is precisely the operating temperature range of a spa hot tub. Therefore, if the water is not changed or cleaned regularly, each milliliter of water may contain hundreds of thousands to millions of bacteria and microorganisms.

To ensure efficient and safe operation, the following items must be kept away from the spa hot tub: Bubble bath liquid, shower gel, soap, shampoo Essential oils, aromatherapy oils, oil-based fragrances Food or beverages Pool chemicals Non-spa-specific cleaning agents etc.

Swim spa hot tubs are typically maintained at a temperature of 33°C to 38°C. Warm water initially dilates blood vessels, followed by slight vasoconstriction as the body regulates temperature. This temperature cycle makes the nervous system more active, thus triggering a "wrinkle response."

The bactericidal effect of chlorine decreases significantly at pH > 7.8, while bromine remains effective within the pH range of 8.0–8.5. This means that users do not need to frequently adjust the water quality in a spa hot tub.