We tried a foam mattress topper, and boy did that thing get hot while we were sleeping on it. Lasted all of one trip. Wife wanted a memory foam mattress, but I was hesitant based on the topper. Ended up replacing the factory mattress with a memory foam with some kind of cooling gels or something and it has been great.
Brian and Tammy
2014 Fleetwood Bounder 35K
Mercury Mariner Hybrid
Blue Ox Baseplate, Blue Ox Tow Bar, Patriot Braking