I bought this California king topper to cut in two for two twin size mattresses for my 5 and 8 year old granddaughters. The 8 yr old said "it's the most comfortable bed in the world now and I love going to bed."  They have said they get hot at times and it bothers one of them. I bought high quality waterproof mattress protectors also which might add to the heat but not sure. I've slept on it while visiting and it relieves pressure points and I slept well. I reccomend this to others.