[quote=Gayle]So, I am exploring airline tickets to get him to Texas but of course big price difference in fully-refundable vs. non. Just looking for feedback, thoughts, experiences.[/quote]
Have you considered getting the cheaper tickets and also getting travel insurance? Most have a "cancel for medical reasons" clause, and some allow you to cancel for any reason.

In September 2010 we bought non-refundable tickets for a trip overseas to visit our son in early 2011. There was a small possibility that my husband was going to have to have back surgery (not cancer-related) sometime before the trip, so I looked into travel insurance. We are members of USAA, and its travel insurance affiliate offered a "cancel for any reason" clause -- while the premiums were 50% higher than for the same policy without that clause, it still wasn't that expensive. (And as it turned out, he didn't need to have surgery -- but it still was worth the peace of mind to know that we could have canceled the trip if we needed to. I believe that at the time we purchased our policy it offered a full refund; now I see it's a 75% refund -- but that's better than nothing.)

I'd think the insurance cost, even with the "cancel for any reason" extra, would be less that the price difference between fully refundable and non-refundable tickets. Note that some policies include a waiver for pre-existing conditions (thus allowing you to cancel because of a pre-existing condition) as long as you purchase the insurance within a few days of getting your tickets and the persons being insured were medically able to travel on the day the tickets were bought, so perhaps you could avoid the "cancel for any reason" extra. As always with such things, read the fine print carefully; if you have questions, call the company (and take good notes!).

If you decide to get travel insurance, I'd suggest buying it separately, and not from the little popup or tick-the-box-if-you-want-it on your airline or travel agency website -- that way you can more easily customize the insurance policy for what YOU would need. If you are members of USAA, search for "travel insurance" on the USAA website -- the link to the affiliate is under "Cruises & Travel Insurance" in the search results (the page itself is titled "Vacations and Travel Insurance"). If you're not, you can go to insuremytrip.com (which offers policies from several companies) or travelguard.com -- both are reputable and have a wide choice of policies/coverage. You can at least price it out and see it works for you before going ahead and purchasing your tickets.