I used to take DS1 absolutely everywhere in a stretchy wrap sling, but with DS2 I barely used it and now with DS3 I would like to pop into town and look around the shops but the thought of the unbearable overheating is totally putting me off 
neither do I want to navigate buses etc with a massive pram with carrycot.
Has anyone else had this or has my body just gone wonky? DS1 was an October baby but my other two were both August, is it just time of year? I honestly can't remember what was different with DS1 but he is nearly 13 now.