Question for my boyfriend, male problems?

Ok now this my seem strange that I'm asking this and even the question but still so here we go

My boyfriend is at home at the moment and he txt me to say that his penis "won't go down" and it's been like that for 45 minutes, he says he wasn't watching anything or doing anything or thinking about anything, this happened on it's own, he says that if it happens for more than an hour it can start to cut off blood supply or something, is what happened dangerous? should he go to the hospital?