This topic has been beaten to death on this forum. Do a search, and you'll see that I agree with the overwhelming majority...
DO NOTHING RELATED TO MEDICINE for it is the last free summer you are going to have ever! Use the 2-3 months to do things outside of the medicine realm, b/c as searly as MSIII year, you may be thinking, "Man, I wish I had like 3 months with just nothing to do, and I could do whatever I want".
You will be thinking medicine practically every single day for a long, long, paingul, agonizingly long and draining time. You are making a mistake by picking up a book to review first year. First year is uselsss. You'd be surprised how low yield first year is for clinicals. Clinicals is all path, pharm, micro, and clinical diagnosis...all of which are mainly taken in 2nd year. Please for the love of all that is holy in this world, and for all us saps, who have crossed the point of no return...ENJOY YOUR VACATION LIKE A PARTY ANIMAL!!