I don't know if they still make them, but Living Textiles made muslin wraps that had a bit of stretch in them, they were awesome.
The other thing about a summer baby, is that I found ours snacked on milk on the hot days, not because he was hungry, but just from thirst, so little feeds to get the foremilk. All the time on the hot days! I remember one day I was a bit upset because I felt like bub was glued to me and I was so hot and grumpy, we ended up giving bub some cooled boiled water.