The biggest risk in EMS is finding out that it's nothing like what you probably expect. Check out
www.traumacentral.com/forums to talk to some veteran EMT's and medics to find out what it is really like. Basically, as a former EMS clinical instructor, I recommend AGAINST people becoming EMT's for reasons than true dedication to prehospital care.
If you want a good "clinical" job, I would suggest phlebotomy. The pay is better than EMS, and the schooling (in places where it is required) is far shorter than EMS. Not to mention if you become proficient with a needle, your patients once you get into medical school will appreciate it!
😉