I am planing a trip with my in-laws, one of whom is sickly. We want to go somewhere warm in January, outside of the US but need to find a place with a decent medical facility just in case. Any thoughts?

San Juan has good medical facilities.

check out this thread:

http://www.fodors.com/forums/threads...p;tid=34845655

So larger US or foreign islands have the better medical facilities?

Are there any particular resorts on these islands which might better for a senior with mobility issues?

Unfortunately islands in the Caribbean (including the US VI's) are not subject to the disabilitiy regulations that are prevallent in mainland US and therefore most resorts are not handicapped accessible althoug many do have elevators if they have multi-level buildings. Some upscale resorts have golf carts that can be made available for those needing help getting around. Your best bet is to pick a few resorts that interest you then call directly tosee what the staff can do for you - often the resort staffs are eager to help.

If you're thinking of St. Thomas, check out Marriott's Frenchman's Reef.

There is also a "Tropical Trolley" that is a really cute bus that takes handicapped cruise ship passengers on island tours. I don't know but they might also include hotel people.

There are some good doctors on this island now also.