I'm applying for a volunteer job at my local hospital, What should I add in the email/letter?

I'm seventeen years old and a junior in highschool. I am really looking for volunteer jobs and I figured my local hospital would be a great place to start. I love the whole medical field and I would really like a future in medical. I want to make sure i get a hold of this oppurtunity, and run with this. Please give me some advice in my letter i'm going to write them. Thanks.
I'm applying for a volunteer job at my local hospital, What should I add in the email/letter?
Okay, to my knowledge, or at least in my very health-care competitive area of Sioux Falls, SD, hospitals don't really DO volunteer jobs of the nature you sound interested in. My sister volunteered for the cancer society after she was cured, but that was a bunch of Word documents and such, if you really want a taste of the hospitable, want to be beneficial, and wouldn't mind getting paid, apply for a tray job in the cafeteria or something, you will get to take trays up to patients, wear scrubs, stuff like that.
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