I'm currently sleeping on a 15 year old mattress. I tried to change the mattress about 5 years ago but could not sleep on it due to heat build up. I have bought a further 2 mattresses all of which I have been unable to sleep on. The problem is the newer mattresses are storing up too much heat which stops me going to sleep. With my old mattress there are hardly any fillings which means my body heat can escape. With newer mattresses the stuffings mean my body heat does not escape the same and I feel hot where I am touching the mattress. I've tried different fabrics on the mattresses - cotton, bamboo, latex - all have been unsuccessful. Has anyone heard of this issue and more importantly does anyone have any advice?