Sure! When the body is immersed in hot water at 38-40℃, the blood vessels in the skin naturally dilate due to the heat. The blood vessels enlarge, increasing blood flow and delivering more heat to the limbs, gradually relieving the feeling of coldness.

Clogged masssage jets not only affect the user experience but can also cause the following problems: 1. Reduced water flow and decreased massage effect 2. Increased load on the heating system 3. Increased risk of bacterial growth 4. Increased noise

While vinegar isn't suitable for directly disinfecting bathtub water, it can be used as a cleaning tool. Many users clean the tub's internal pipes, showerhead, surface, and limescale buildup with vinegar after draining the tub.

In public swimming pools or spas, hygiene standards generally require users to rinse thoroughly before and after entering the pool/spa to reduce the risk of contamination and cross-infection.

From a skin health perspective, spa jacuzzi bathtubs are gentler, promoting skin hydration and blood circulation, while saunas are more suitable for oily skin and those with a high metabolism.

Thermal therapy studies have shown that immersion in water around 40°C for 15 to 30 minutes can increase skin blood flow by 30% to 50%. Combining a spa hot tub with jet massage can enhance local muscle blood flow and accelerate the excretion of metabolic waste.