I have worked at a Fire/Rescue company for 5 years now, mainly as an EMT, ambulance driver, and squad EMT. It has come up at every interview that I've had and I believe it adds a lot to your application and chances of being accepted. If you are able to talk about your responsibilities such as crew and resource management and patient responsibilities, it shows your maturity and ability to interact with patients and future success in medical school. ALso, it shows a commitment to the community and service, something that I think schools like to see in their applicants. I have talked on average of 15 minutes in an interview on my volunteer experience alone.
However, I started when I was 16 and have many things that I can talk about from my experience and can address anything that the interviewer may ask me, ranging from patient exposure, to the EMS system as a whole in the county and how it functions. If you plan on just taking the course now, I believe it will add little to your application, other than just showing you took an EMT course.
Overall, its been a great experience and has helped me a lot in the process, especially because my shift officer wrote me a ridiculously good letter of recommendation. Schools want to see a commitment to an activity over a longer period of time than just a few months for a course. That is my take on it and I hope it helped....best of luck to you in this process!