I wish you luck. Working 108 hours over thirteen days, having a day off, and repeating that cycle made me want to hurt people by day 27. I actually considered punching my boss when he asked me to come in the one day I took off.
Chemistry grad students (at least for organic chemistry) typically work ~75-hour weeks. Usually that’s just 6 days, but some like to spread it out over 7. Nothing terribly arduous or hardcore about it; that’s just how it’s done. It’s not until you pass 80 and start pushing 90 that things start to suck.
Granted, that’s a job that involves moving about, not being stuck behind a wheel all day. Ugh.