Wear one or get none.
People like to enjoy themselves first and then worry later. The clinics are full all year long.
I was in the Navy when I was a kid, and on one cruise, we sailed around the world, most of it in the Indian Ocean. About 3 days after we'd leave port, and we hit alot of ports, there would be a long line outside the Corpsman's "office", and he would be handing out penicillin to each visitor. Apparently, the penicillin killed whatever caused whatever STD was prevalent then, and it was also to treat tuberculosis.
All the officers were diagnosed with TB, and treated accordingly, and an entry was duly made in their service jackets. Everybody else was diagnosed with a social disease, and that blushing entry followed them for the rest of their Navy days.