I think it started with preemies; it's very important to keep a premature baby's head warm. It kinda spread to "Santa babies" from there. But these days, many hospitals have a small army of volunteers who knit or crochet baby hats that are given to little ones when they are born; particularly during the cooler parts of the year. I still have the ones that were given to my two.Did Rachel by any chance knit that cute hat Alice is wearing....?