Merino wool socks for me, too. Since I discovered them I haven't worn anything else and replaced all my other socks. I even have merino sneaker socks for summer. My feet feel always comfortable.
I wore them in temperatures above 30° C with no problems. This summer we had some really hot days in Germany, up to 38° C. Last friday it was 33° C here. If that's not hot enough I can't say anything about it. If I wear socks I wear merino wool. If not I go barefoot (which isn't an option in really hot weather because it burns the sole of your feet...)!Yes but you're talking about a European Summer. The OP specifically said he's going to a hot climate. We must assume he means somewhere that truly is hot.
I wore them in temperatures above 30° C with no problems. This summer we had some really hot days in Germany, up to 38° C. Last friday it was 33° C here. If that's not hot enough I can't say anything about it. If I wear socks I wear merino wool. If not I go barefoot (which isn't an option in really hot weather because it burns the sole of your feet...)!