An Idaho woman was treated for hypothermia earlier this week after she was found "sleep swimming" in a river in the middle of the night.

According to the Cassia County sheriff's report, the unidentified 31-year-old woman—who has an apparent history of sleepwalking—left her home in Burley, Idaho, barefoot and in her pajamas early Tuesday. Her husband called the sheriff's office at 2:25 a.m. to report his wife was missing and a sliding glass door had been left open.

Neighbors and a search and rescue team began combing the area. The woman was found "wet and hypothermic" on the side of the Snake River about a quarter mile downstream from her home. She was taken to Cassia Regional Medical Center and treated for hypothermia.

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According to the Magic Valley Times-News, police say this was the third incident in the last five weeks involving the woman:

Deputies located her one other time disoriented and soaking wet in the city of Burley after apparently swimming in the river.

Following Tuesday's "sleep-swimming" episode, a Cassia County judge "issued an order to have the woman's mental health evaluated."

According to the A.D.A.M. medical encyclopedia, sleepwalking or "somnambulism" most often occurs during deep, non-REM sleep early in the night.

Sleepwalkers "may get up and walk around, or do complex activities such as moving furniture, going to the bathroom, and dressing or undressing. Some people even drive a car while they are asleep."

The cause of sleepwalking can be fatigue, lack of sleep, anxiety, alcohol and sedatives, or medical conditions such as partial complex seizures and psychiatric disorders including "post-traumatic stress disorder, panic attacks, or dissociative states, such as multiple personality disorder."

[Related: Sleepwalking more common than suspected]

According to WebMD.com, "the sleepwalker is unable to respond during the event and does not remember sleepwalking." It occurs most commonly in childhood but can last into adulthood.