Deaths and dozens of drug overdoses at summer music festivals have prompted B.C.'s coroner's office to warn Squamish Music Festival goers this weekend to practise safe consumption of party drugs.

Health officials and emergency responders ​in Penticton, B.C., were overwhelmed last weekend after one person died and 90 concertgoers at the Boonstock Music Festival were hospitalized for drug overdoses.

Lynn Tolocka, a 24-year-old woman from Leduc, Alta., died from a suspected overdose.

In Toronto, police identified two types of pills linked to overdoses at the Veld Music Festival there this past weekend.

Veld music festival - video thumbnail

Police say two people died and more than a dozen others fell ill after they ingested drugs purchased at the Veld music festival in Toronto over the August long weekend. (CBC)

Two people died and at least 13 people fell ill after ingesting party drugs during the two-day music festival held at Downsview Park.

"Don't trust your drug dealer. The quality control is poor," coroner Barb McLintock with the B.C. Coroner's Service said.

"A lot of young people believe rave drugs and ecstasy drugs are safer to use because they're not drugs of addiction like heroin and cocaine, but they forget people have idiosyncratic reactions to those drugs."

McLintock said an idiosyncratic reaction means nine people may be fine after consuming a drug but a tenth may have a potentially fatal reaction to the exact same drug because of a biochemical issue.

"I'm not so naive as to think people won't take drugs at music festivals. If you absolutely feel you have to, keep people around you all the time and if you see someone else in distress, get help now. Don't wait 10 minutes."

McLintock said the weather forecast for this weekend for the Squamish Music Festival is supposed to be hot and dry. Heat and dehydration will exacerbate the effects of party drugs, she said.

Big security presence

nick phongsavath

Nick Phongsavath, 21, died at the Pemberton Music Festival in B.C., but the cause of his death has not been released. He was a student at the University of Regina. (Facebook)

At B.C.'s Pemberton Music Festival last month, one person died. The cause of that death has not yet been determined but police have ruled out homicide.

Squamish Music Festival director Paul Runnals said officials are prepared for all emergencies. Headline acts at the festival this year are Bruno Mars, Eminem and Arcade Fire.

Crews who formerly worked for the Vancouver Olympic committee have been brought in to deal with traffic congestion, 500-plus security guards will be on site and the RCMP will also be in attendance.

Eight full medical tents have been set up for the 16,000 concert goers expected to attend the festival. You can see inside one of the medical tents by watching the video above.

With files from CBC's Brady Strachan and Richard Zussman