It's a leaf suit. I use mine all year and just pull it on over my progressively heavy clothes. I recommend the type that has mesh as the garment since it will help with mosquitoes. Early season I wear tee shirts under it and that's usually it. It's hot your going to sweat watch the wind and you'll be fine.
+1
I've bought the Red Head brand, Cabelas brand. Just get one that won't be hard to get on over heavier clothes.