You need to contact an academic program.... that is about the only way you are going to get your foot in the door. The other option is a friend of a friend that is an EM physician in a private place; you can try the volunteer thing to get your foot in the door, but I think its rarely all that successful.
During college, in my hometown we had no academic center. I signed up as a volunteer at the hospital; originally I was in the ED. All I got to do was sign in vistors at the front. I had zero interaction with the actual ER or patients and tried to get to know the folks there but had virtually no luck. I talked with the volunteer supervisor and ended up in the post procedure GI lab. I did get to interact with patients there and one of the GI docs, who took care of several of my family members through the years, did take me into several procedures and also got me into the OR for some cases.
I was doing the above for pre medical school experiences...
Most private physicians just dont have any interest in having a student around; and even if they do, its not just up to them. It then has to go through the channels of adminstration and such...so it becomes a huge headache all the way around. I've heard people having better luck in a stand alone family medicine type clinic owned by the physicans. They do not have the adminstration layer that most any ER has...