A hot tub is a large tub or small pool full of heated water and used for soaking, relaxation, hydrotherapy, reading, or meditation. Hot tubs are frequently located out-of-doors although they may be sheltered against sun, rain, wind, or snow.
There are essentially three different styles of hot tubs:
Simple wooden-staved soaking tubs
Fiberglass-reinforced plastic spas (whirlpool tubs)
Bathtub-sized indoor units
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