Review on Comfortable and Stylish: AVAUMA Baby Boys Girls Snug-Fit Cotton Pajama Set for Daily Sleepwear by John Roberts

We bought this to use as a pad, not pajamas. It's made of thick, soft cotton and my son says it's very comfortable. We first tried it at home (low 70 degrees Fahrenheit) with no clothes over it and my son started heating up right away so we had to take it right away. We've since used it under my son's light Halloween costume in fairly mild temperatures (low 60s) and it's kept him warm. That being said I'm pretty sure it will work very well as an undercoat in lower temperatures. Note that where we live the definition of cold is about 40 years. Finally evaluate. My son was a size smaller and we took a size up. The larger size suits him well, there is room to grow. The material is very stretchy and the large size is also good for his small frame (he is very skinny).