Obtaining NIH Internship

<p>Hi, I was trying to obtain an NIH internship next summer and I was wondering if the only way is through contacts. Also I heard that if you get to know some PIs through email, that it really helps. I was wondering how one would get emails of PI, how they would help throw a word in their for you, and just plainly as well, how do I get an internship at NIH?
Notes:
I attend, a Science Math and Comp Sci Magnet HS, that requires an internship and have some contacts with the major institutions, does that help?</p>