Newborns in hot car with no A/C

Hello
My family are so excited to see our little man who will be due tomorrow. They keep asking me when the next time we will be out to pick up some more stuff they got from us and I keep telling them probably a couple weeks or a month. The A/C in our car went out and my boyfriend doesn't have the time to fix it right now. We only live 3 minutes away from the hospital so driving him home won't be a problem but me and my boyfriend live in tooele Utah and my family all live in salt lake. The drive isn't bad it's probably 20-25 minutes depending on the traffic. But being a FTM I don't trust putting my newborn in a hot humid car to go to salt lake and back. Has anyone ever tried this and did it work out well or do you think it will be completely unsafe?