Dozens of concertgoers have been brought to an Okanagan emergency room since the Boonstock Music Festival got underway on Thursday — many of them sick after ingesting various quantities and combinations of drugs and alcohol.

Grace Kucey, spokeswoman for Interior Health, said that over the course of two days, paramedics brought 43 people to Penticton Regional Hospital from the festival grounds.

Penticton RCMP became extremely concerned Saturday after learning of the dozen or more people had already been treated in hospital for drug interactions, and issued a public plea for festivalgoers to use caution. (Boonstock/Facebook)

"The majority of presentations to the hospital have been drug and alcohol related," she told CBC News on Sunday.

Paramedics brought 26 people from the festival site to the emergency room in the 24 hours from 7 a.m. Saturday to 7 a.m. Sunday, Kucey said.

That number tops the 17 transfers counted in the previous 24-hour period — a number that includes two people who RCMP said were in critical condition, and a 24-year-old woman from Alberta who died from a suspected overdose.

Penticton RCMP became extremely concerned Saturday after learning of the dozen or more people who had already been treated in hospital for drug interactions, and issued a public plea for festivalgoers to use caution.

"Police are asking all Boonstock attendees to refrain from ingesting unknown substances and to ensure that they remain hydrated in the hot, dry, dusty conditions of the event grounds," Const. Kris Clark said.

In a 48-hour period ending at 7 a.m. Sunday, at least 43 people were taken by paramedics to Penticton Regional Hospital. A spokeswoman said the bulk of those cases were related to drug and alcohol interactions. (Boonstock/Facebook)

Police also warned on Twitter that dehydration greatly increases the risks of drug and alcohol overdoses.

Interior Health​ said that despite the sudden surge of new patients in Penticton, hospital staff members are coping.

"The hospital is managing patient load very well," Kucey said. "The access to the medical mobile unit, which is on site, will be used if needed, but currently the hospital is managing well."

The festival, which is in its final day and comes to an end in the early hours of Monday morning, was predicted to draw 8,000 people to the festival grounds, near the north shore of Skaha Lake.

The Boonstock Music Festival relocated to Penticton, B.C., this year after nine years north of Edmonton in Gibbons, Alta.