I live on the Gold Coast in Australia and it is not at all cooling. In fact I would say its hot. The softness (yes very soft) almost clings to you like a static way and after a few minutes, you're boiling. Its cool to the touch but not for long. This is probably great for normal environments but if you live somewhere hot, invest in good linen or cotton sheets. Also, I found mildew on mine with the humid weather. So I would say easy to mildew with humidity. More on reddit.com

Bamboo is basically a synthetic material because of how much processing it takes. If you are looking for cool and organic that would leave percale cotton and linen. Tencel lyocel is a semi synthetic fiber but doesnt require carbon disulfide like bamboo so better for workers and enviroment. I super reccomend tencel lyocel. Its super cool and a more silky texture. If you dont like a silky texture then go with cotton percale or linen. Cotton is softer than linen but linen softens over time. I would recommend this set from target or this comforter from ll bean which is super lightweight. Im obsessed with ll bean cotton percale sheets. So crisp and cool. https://www.llbean.com/llb/shop/113442?page=ultrasoft-cotton-comforter-ii&bc=31-131-1158&feat=1158-GN0&csp=a&attrValue_0=428&pos=1 https://www.target.com/p/3pc-king-tencel-174-comforter-and-sham-set-light-teal-green-threshold-8482/-/A-89158555 More on reddit.com

If your room is too hot that's what you need to fix. No comforter actually has a cooling effect — they're all warmer than no comforter. A plain sheet will be warmer than no sheet. Where do you get the idea that there are cooling comforters? Maybe what you need is Bed Jet ? More on reddit.com

For starters, absolutely no comforters! They are too heavy, and stuffed with polyester fill. Likewise, dont use any bedding material that is anything less than 100% cotton, linen or silk. Nothing with polyester, nylon, rayon etc. Natural fibers are breathable and cooling. Synthetic fibees are like wrapping yourself in saran wrap. I suggest a 100% cotton sheet set, and a 100% cotton blanket. No comforters. If you can afford it, a silk pillowcase would be bonus as silk becomes the temp of the surrounding air More on reddit.com