I agree with the earlier response about avoiding the massages as some people have major issues with touching or being undressed around others but if they are women, a lot of the spas also have additional services that they could use a gift certificate for (not so much for men though). A handwritten note from yourself (and from your kids if they are old enough to do so) will probably mean the most to them but because I also like to get something in addition the dinner out is a good idea if no spa certificate. If they were men (or even women) and your hubby knows anything about their hobbies or likes a gift certificate aimed at that might be good also (i.e. golf, crafts, etc.) Glad he is okay and that he was with people good enough to show they care.