I ran out of transmission fluid due to a break in the tubing. Can I idle in Park with no transmission fluid?
I don't know what year your vehicle is (240 Volvo's I think were primarily in the 80s and 90s), but most vehicles of that era with automatic transmissions have the main pump being directly driven off of the torque converter. If you run your engine with a dry (or even mostly dry) transmission, you'll end up frying the pump and therefore the transmission will be damaged. Definitely not something you want to do.
Looking at the torque converter, it appears by the two notches in it, it does run a pump up front: