Kelowna RCMP are investigating whether a potentially lethal batch of heroin is circulating the Okanagan after two drug users were rushed to hospital Friday night.

The men were stumbling through downtown Kelowna showing signs of intoxication when police picked them up, Const. Steve Holmes said. They were coherent and cooperative at first, but their condition quickly worsened.

"Basically their core temperature began to increase. They were sweating profusely, acting uncontrollably. They were flailing, grunting, and sometimes just screaming out," Holmes said. "Then they just lost control of their muscles, they couldn't control themselves."

The two men were rushed to hospital for treatment. They both admitted to using heroin, and one man admitted to using crack cocaine as well.

"The doctors said if they had not been found, they may not have survived," Holmes said.

Investigators are trying to determine whether the men were suffering a drug overdose of if their heroin was tainted. In the mean time, local drug users are being warned to watch out for a bad batch.

"We're talking to people who are addicted. You don't know what you're getting with drugs like heroin, so protect yourselves as best you can," Holmes said.

While "safe" illicit drug use is difficult, Holmes said if users are supervised by a sober party their lives could be saved in the event of an emergency.