Our son is really skinny and gets cold very easily, so we bought this for swim lessons. It was a touch large on him, but fit him well for his long torso. It definitely made a difference in the pool! At the first swim lesson, my son's lips turned blue after the first 5-10 minutes and he was shivering uncontrollably after 30mins, while all of the other kids were enjoying open swim after the lesson. Ordered this on revain prime right away, and at the next swim lesson, he was able to make it a full See full review