Safe to turn on heat?

I recently got my own apartment for college and it has a hot water

heater and a circulating pump to get the water to the radiators. Well, I

turned up the thermostat for the first time today and went over to the

boiler room and noticed the the black needle on the altitude gauge of

the water heater was a little higher than it was earlier (about 29 for

pressure..i'm assuming psi, but there weren't any units on it). I

checked about 5 minutes later and it was 32! It kept on increasing and

was already in the "danger" zone when it hit 30. I freaked out and

turned down the thermometer...but I obviously don't know much about

heating/cooling and was just curious as to why it's reaching this

"danger" zone and what I should do? The maintenance man never told me

what to do regarding the heat and when I mentioned a problem with the

circulating pump before (it constantly runs all the time) he said he

needed to install a new thermostat but never got around to it. I

asked this question on yahoo answers and received an answer saying the radiators probably need bled. My question is however..is it safe to turn the heat up until the maintenance man get's a chance to fix it? I really appreciate the help!