Hot tubs use very well-heated water to loosen the muscles and generally relax the body, and most often utilize water jets to massage and further promote a hydrotherapeutic experience. Hot tubs are often located outdoors.

A new law that went into effect in December 2008 requires pool and hot tub owners to install new drain covers and grates to prevent people from being sucked into the drain or trapped in it. The law is named after Virginia Graeme Baker, who died at the age of 7 after being sucked to the drain at the bottom of a hut tub.CNN: Some ignore law to prevent pools from being child deathtraps (January 15, 2009)

Hygiene is important in hot tubs and involves a combination of the chemical balance of the water, draining and cleaning and having a clean water filter.

"Jacuzzi" has become a term that is synonymous with "hot tub," but it is actually a brand of hot tub. The California company has been around since 1915 and purports to be the inventor of the portable hot tub.

"Whirlpool" is also used as another name for "hot tubs," but it, too, is actually a company that makes hot tubs among many other appliances. The Whirlpool Corporation has been around even longer than Jacuzzi, since 1911.

The federal law Virginia Graeme Baker Pool and Spa Act went into effect in December 2008. It requires pool and hot tub owners to install new drain covers and grates to prevent people from being sucked into the drain or trapped in it.Post Independent: Local pools getting caught up on new drain regulation (December 21, 2008)

• Wikipedia: Seinfeld - "The Hot Tub" Episode