[kijin]

Your bed needs to be breathable. That's the single most important thing. A cool bed without proper ventilation will attract condensation and mold, and make you feel damp.

A good spring mattress sitting on top of slats will never get uncomfortably hot or cold in any particular spot, because air moves freely in and out, powered by your own body movements.

The mattress should also be as firm as you can tolerate. A firm mattress leaves breathable space between some parts of your body and the surface of the bed, instead of allowing your body to sink into the foam and become insulated on all sides. Again, airflow is key. Regardless of what heating or cooling solution you have, airflow will multiply its effect.

[switch007]

Trouble is the spring mattress manufacturers kept reducing quality to achieve a price point and then people needed the extra comfort they took away, for cheap, so hot, foam toppers became the norm.

If you want an all-natural, chemical-free, traditional hand-made pocket-sprung mattress you’re looking at £3-6k here in the UK. But I agree they are the pinnacle of mattresses, ticking every box

[globular-toast]

I'll add to this I find a wool blanket/duvet to be so much better than polyester/plastic. When I use plastic duvets in hotels etc it feels like I'm wrapped in a plastic bag.

[kijin]

Completely agreed. Natural fibers like wool and cotton help moderate humidity by quickly absorbing moisture and slowly letting it evaporate.

Synthetic fibers can be designed to channel moisture away from your skin instead of trapping it, but they can't absorb any. Besides, I doubt that hotels use sportswear-grade stuff in their duvets.