they make deep pocket fitted sheets (14" deep corner pockets for mattresses
with thick padded toppers), adelle.  should work with yours.  problem is you
have to ask where they are, or what brand, or really look for them in the
stores' linen departments.  i used to get them at most places.

also, there are little elastic bands, with suspender-like clips on them,
that work great at keeping the sheet from riding up the mattress -- cost
about $2-$3 for a set of 4 at bed, bath & beyond or at linens & things.  (i
have to use those for my wallhugger tempurpedic, or else any size bottom
fitted-sheet winds up off the corners and on top of the mattress.)

kate

I bought mine at Costco, so it is probably the same one.

We bought a Queen size. Had the usual out-gassing issue for a week or so
(irritated my asthma). Is a little too big for my boxspring. Wound up buying
king size sheets so that sides actually stay covered by fitted sheet. Queen
size fitted sheets do fit in the corners, but the sides ride up exposing the
mattress.

Love the comfort. Sleep has improved dramatically (can sleep 4-6 hours
instead of two at a time) but still wake with pressure point issues during
'bad' phases. I do overheat sometimes.

Adelle - cleaning up from prep cooking