I'm wasn't kidding when I say that among snake breeders (especially BPs) that IBD is something everyone fears because it can wipe out a breeder's collection & investment or livelihood- so we try hard NOT to jump to any conclusions when someone has a snake with neurological symptoms (corkscrewing- unable to right itself- etc.) because it's NOT the only thing that can cause that.
Besides overheating, the over-exposure to some chemicals- pesticides- can sure cause this too. But I have to bring it up now so you're aware that it's a possibility with the symptoms this snake has. It's also underweight & the inability to eat is an issue with IBD too. So since it's unlikely you'll test for it, & may want to get another snake... Your source of this snake- no telling how much he knows, & maybe he's in denial & wanted to blame over-heating- so I would just rather have you be "safe than sorry" in case this snake is NOT suffering from a "heat injury". There's no way we can know for sure right now. Again, so sorry...