Cruise ships are an environment unlike any other when it comes to the spread of disease. You have sometimes as many as 8,000 people from all over the world crammed into a boat together for a week or more. That means that each elevator button, hand rail, tongs in the buffet, counter tops are touched thousands of times each day and unfortunately, not everyone is 100% healthy. While you can protect yourself from others, sometimes it is YOU who is the sick one. Here's what to do if you catch a cold while on a cruise ship.