Replying to Friend passed out, had a seizure thing..

so last weekend at a party my friend passed out after 15 beers, a few shots, some weed, salvia and some knife hits. he passed out at like three in the morning on my friends parents bed and pissed himself and threw up everywhere. so at like five we cleaned all the shit up and drug him downstairs and into his car. i was sitting in the drivers seat and he was right next to me in the passenger's seat.

then he started like uncontrolably shivering and shit and like spitting. it was fucked up and kept like shaking him and he was just passed the fuck out. i didn't think he could be too cold cause it was like 50 out (we live in ak). so i drove him around for a while and then realized his car didn't have any heat. so i parked him on a sideroad like a half mile from my house and walked home hoping he would be fine. he was shivering like the whole time but started to wake up a bit by the end.

talked to him the next day and he felt like shit but he was fine. anybody else have somethin like this happen? or know why he was all full body shivering and spitting and shit? scared me pretty bad when i thought about it.