01/27/2012 at 01:05 PM EST
was having convulsions and "burning up" at her Los Angeles home after she smoked an unknown substance, according to the 911 call tape released Friday.
"She smoked something. It's not marijuana, but it's similar to it. It's similar to incense," said a female caller. "She seems to be having convulsions of some sort."
The caller adds, "She's semi-conscious, barely. She's convulsing."
A second woman also gets on the phone and says, "She's shaking, convulsing, burning up. I'm taking cold water and putting it on her back because she's burning up."
At one point, the woman is heard saying, "Demi, can you hear me? Yes, she's squeezing my hand. She can't speak. She's convulsing so we're holding her down."
A rescue crew arrived 10 minutes after the call went out at 10:49 p.m. Monday night. Moore, 49, was then rushed to a local hospital
At least three women and a man were heard speaking on the tape. At one point, someone refers to a person named "Ru" who's in the room, a possible reference to Moore's daughter, Rumer Willis
The actress, who split
from husband Ashton Kutcher
in November, has sought professional help for what her rep calls "exhaustion" and to "improve her overall health."