A decent mattress is the most important thing we can have. I suffer from back issues and literally shit myself when sleeping in hotels. You know you are in trouble when your head is up and so are your feet meaning you are sleeping in a boat like bed. I have learned to pay a little extra and not risk visiting chiropractors and physios abroad. Memory foam is good, but be careful as it changes with heat. The hotter it is the less support it offers.