It was unbearably hot in Fes when I visited. Luckily, we had an AMAZING airbnb we were staying at. It turned out to be this old palace which was SUPER cheap to rent on airbnb. Our hosts were incredibly nice and made us dinner and breakfast (hands down the best meals I had while in Morocco). When we decided to bear the heat and walk to the medina, we went to Chouara tannery, which still functions nearly the same as it did hundreds of years ago.