Hot springs are ponds, portions of a lake, or pools in which water has been naturally heated underground. The body of water housing hot springs can vary in size. Geologists think a particular combination of rocks and minerals found underground work together to create hot springs. It is believed these rocks and minerals trap hot springs and allow them to become fermented, which heats the water up. The heated water becomes sterilized and cause bubbles to rise to the surface.

The temperature of the surface waters must be well over the normal ground temperature in order to be considered hot springs. While the ground temperature in many areas averages 57ºF (13.9ºC), hot springs reach temperatures in the low to mid-100s (37.8 to 65.6ºC).

Throughout the United States, a number of locations boast natural hot springs. Arkansas houses the most popular location, Hot Springs National Park. The park was designated a National Park in 1832, which provides the hot springs with special protection. This has helped keep the hot springs from being damaged by tourists or business ventures.

Hot Springs National Park is located in the city of Hot Springs, which is approximately a one hour drive southwest of Little Rock, Arkansas. It is open year round, seven days per week. The water in the hot springs is very pure and reaches temperatures as high as 143ºF (61.7ºC). A number of hiking trails, picnicking areas, camping areas, and bathhouses can be found throughout the park.

The majority of the bathhouses at Hot Springs National Park are kept locked throughout the day and are operated by private firms. Accessing the bathhouses typically requires payment of a set fee and sometimes an appointment. A full body massage at the bathhouses typically includes a bathing experience within the hot springs, a manicure, a pedicure, and a facial and body scrub.