Number of hours can also be misleading. I work 40 hours a week at one job. Someone who worked 40 hours a week at three jobs would certainly have more difficulties at work, like more commutes, more context switching, not having the benefits that arise from a full time job, etc.

It does matter how many jobs you work though, because low-wage employees arrange things so nobody gets 30 hours a week to qualify for full time benefits. Also the kinds of jobs that people who work 3-4 jobs often work typically have chaotic schedules that aren't set well in advance, meaning that they inevitably come into conflict creating stress and the potential to be fired for not being able to show up at one of them.

The issue is each job might have you on call.

So you can have some 80 hour work weeks and 8 hour weeks.

the film industry, sleep, and driving one sparked a memory. i took a film production elective while completing my undergrad. The class left and I stayed behind to finish up. A while later, they walked back in. Confused, I wondered if they all forgot something. Nope. Turned out it was the next class session! I hadn't moved in nearly 24 hours, and was awake at this point for at least 40 hours. I then had over an hour drive home up a curvy mountain road (at night) with thousand foot cliffs.

I actually full on hallucinated.

1/3: A giant SUV (20' tall) was reversing onto the highway. I slammed on the breaks only to realize it wasn't there.

2/3: A bit later, a hundred foot tall heavy woman in a moo moo standing akimbo over the road. I recall telling myself to not look up as I passed underneath.

3/3: someone reversing their boat and trailer onto the road, but the boat was 20' tall (my mind had _something_ going on with giants I guess). By that point, I just drove through the illusion, and, after, realized just how scary that was.

Finally got home, and I recall aiming for my pillow and being asleep before hitting the mattress.