What should I do?

My fiancé and I just got back from a friend's place half an hour away. He's passed out drunk in the passenger seat, and I was super pissed off cuz he didn't wanna leave when I did, but I wanted to leave before he got to the point of drunk he's at. I've brought out blankets and covered him up, laid the seat back, and made him a pillow, but it just breaks my heart to leave him out here. I'm mad at him, but I'm literally bawling. I love him to death, and I've already spent over half an hour trying to wake him up. He almost got up once, but laid back down. I don't want him to throw up and choke or anything.. he's not laying flat, but still. What would you do?

Edit: here's the hourly weather