The association representing the spas in Quebec is calling on people to be cautious when choosing a spa after a woman died following a detoxification treatment at a facility near Drummondville.

Chantal Lavigne, 35, died in hospital Friday.

Police said Lavigne had undergone treatment at the Reine de Paix farmhouse in the town of Durham, about 100 kilometres southeast of Montreal. She was one of about 10 people taking part in a lengthy detoxification session.

"The treatments consisted of a process of sweating by being all wrapped in plastic with mud, and also with blankets," said Sgt. Éloise Cossette.

Quebec provincial police spokesman Daniel Thibodeau said Lavigne and another woman were rushed to hospital in nearby Drummondville. "One was in critical condition when we found her, the other was suffering from serious vomiting," Thibodeau said.

Lavigne died Friday afternoon, while the other woman was in stable condition Saturday. Both women were also encased in cardboard boxes.

Police were trying to determine if negligence or criminal conduct was involved.

Spas in Quebec are not regulated, said Lucie Brosseau with Alliance Spas Relais Santé, which represents some Quebec spas. Brosseau said the association has developed standards for spas to follow, but they are not mandatory.

She said it is important for individuals seeking spa services to do the appropriate research before receiving treatment.

"One thing we want with this incident is to [get] people to go and look and ask for quality," she said. "Ask for quality therapists, ask for quality treatments."

Quebec provincial police are investigating the woman's death. Another woman was hospitalized and is in stable condition.

Police say at least 10 people were undergoing the same detox treatment, which lasted for several hours, and did not include drinking water.

The farmhouse is rented by a woman who offers an initiation to Reiki, a practice developed by a Japanese Buddhists in the 1920s.

Neighbours have previously complained to police about the farmhouse after hearing loud screaming on the property.

"The screaming was odd, it gave me shivers," said neighbour Roxanne Labonté, who called authorities a month ago to complain about the noise.

The spa specializes in Reiki therapy, and offers energy therapy, massage and natural products, according to an online listing.

The woman who runs it, Daiva Goulet, could not be reached for comment Saturday afternoon.

With files from The Canadian Press