Very breathable. The solid latex pillows typically have lots of perforations for air circulation. I just got two of these pillows from Brooklyn Bedding, and I didn’t know a pillow could make me so happy:

https://brooklynbedding.com/products/talalay-latex-pillow

It feels like the perfect combination of supportive and soft. I’ve had a latex mattress for several years and absolutely love it, so I figured I’d also like a latex pillow. I haven’t tried washing them yet, but they come with an organic cotton cover that’s washable. They recommend spot cleaning the latex inserts.

I second the latex.

Your not gonna find one you like without researching the specific material and finding the specific pillows then spending hundreds to thousands ordering and trying them all. That’s what I had to do anyway. I wound up at latex.

Very breathable and not anything like memory foam. Latex doesn't sleep hot like memory foam, and latex actually has bounce to it unlike memory foam.