A group of female friends in their 80s almost died after getting stuck in a hot tub during a getaway, with the temperature of its waters making them seriously-ill.

The trouble began after the unidentified friends booked a vacation to the remote wilderness of Campton in Wolfe County, deep in the Appalachian Plateau of Eastern Kentucky.

On spotting the hot tub, the friends decided to get in to relax after a busy day of catching up. But disaster soon struck.

Two of the women could not get out of the tub because of pre-existing health issues and started overheating to a point where they became hyperthermic, according to the Wolfe County Search and Rescue Team (WCSART).

Hyperthermia is when the body's core temperature exceeds its normal level, leading to anything from a heat rash to a potentially fatal heat stroke, according to the Cleveland Clinic.