I am starting my Camino in San Jean's on 23rd May will my 1,000 mile socks make my feet over heat. I broke my ankle a few years back and when I walk I like the the support the 1,000 mile socks give your tendons, but don't want to over do it in the summer.
I wore 1000 Mile FUSION socks (double layered, as yours might be, but there is a difference in what they sell) for both Caminos, and on this last one, the del Norte, it was 90-97 degrees for the first week. My feet didn't get hot at all. And I felt so comfortable walking with those socks. I left my boots (from the first Camino) home, and wore (I know everyone has favorite shoes that work, but I'm just saying) Keene Targhee II lower cut hiking shoes. On my first Camino, my boots AND my shoes were a nightmare, and I ended up buying Teva hiking sandals to wear with the 1000 Mile Fusion socks.
This time my choice of shoes AND my 3 pair of 1000 Mile Fusion socks were wonderful. The trail was very very difficult for the first week or so, exacerbated by my bronchial infection. But the socks? NO blisters on either walk.
So I "ditto" Wayfarer and crackmrmac. Buen Camino. And I can't believe I'm typing this, but I've been thinking about which path I will walk for my THIRD Camino . . .