Hot tubs are a common amenity installed in hotels, fitness facilities, and athletic training rooms. One of the oldest forms of heat therapy, hot tubs have been used for recreational and restorative purposes since the Roman Empire. While most people are familiar with hot tubs using chlorinated or bath water, salt water hot tubs have some unique and beneficial characteristics.

Salt water has a natural sanitizing effect that fresh water does not. The sanitizing effect of salt means that a salt water hot tub needs less chlorine for disinfection than a fresh water tub. Less chlorine means fewer irritations to the skin and eyes. With fewer chemicals, a salt water hot tub also has a more natural smell.

The combination of heat and salt water can be an effective way to treat swelling and edema, notes the National Strength and Conditioning Association. The hot water opens pores, while the salty water draws fluid out of the skin. Salt water hot tubs can be used to reduce painful swelling from overexertion and exercise.

Salt water hot tubs, especially ones with whirlpool capabilities, can be used to release both physical and psychological tension. Hot water helps relieve muscle tightness, while the water jets can massage and further loosen muscles. While hot tubs are often used by athletes for their restorative effect on muscles, everyone can use them for relaxation.

One of the disadvantages of heavily chlorinated fresh water hot tubs is their drying effect on skin. Salt water, by contrast, has a softening effect on skin. Salt is a common ingredient in many skincare products.

According to the Arthritis Foundation, heat therapy methods like hot tubs can be used to relieve joint pain. In addition to the pain relief from the heat, the water provides an almost weightless environment that relieves stress and pressure on joints.