As has been mentioned, EMS in the city itself is run by Philly FD. The department and it's EMS system is broken beyond repair. Too broken to go into much detail here. However, by living in the city you are taking your life in your hands. It is not uncommon for local news outlets to report on someone dying, someone who might otherwise have lived, because they had to wait in excess of 40 minutes for an ambulance. You may think I'm kidding, but I'm not.
If you were thinking of working for Philly Fire, ambulance staffing is primarily dual medic. The BLS ambulances filling the tiered response description are staffed with FFs who are either being punished for something or are on OT. (Draw your own conclusions on the quality of care provided.) They aren't hiring BLS providers to primarily staff ambulances.
The ambulance companies listed in another response are primarily medical transport companies. You won't be faring any better working for them in Philly than you are working where you are now in Chicago.
Some hospitals may, potentially, hire EMTs as a tech of sorts. Most seem to prefer medics for these jobs. But look at Penn, Hahnemann, Jefferson and Temple (and their respective hospital systems) to see if they have anything that might be up your alley. You can try Einstein, too, but you're taking your life in your hands in North Philly. (Actually, now that I think about it, I did know a guy who was an EMT B who worked as a tech in the ER at Einstein. I don't know if they still hire EMTs but it is certainly worth a look.)
If you're looking for street work look to the surrounding counties. Delaware County and Montgomery County have 911 services galore but finding full time work as a basic will be difficult (but not impossible).
Avoid New Jersey like the plague.
Avoid New Jersey like the plague.
Did I mention you want to avoid New Jersey like the plague?
Drexel is a good school. It's a shame it's in such a dump of a city. Good luck with school!