I buy base layers for my kids each fall, although they last for at least 2 years as my kids grow - somehow the material seems to grow with them! I recommend sizing up to get the most out of your base layers for kids. So warm, so soft... My daughter's favourite thing to wear (she often wears them as regular clothes, not base layers). Keeps her warm under her snowpants and cool when she get her winter gear off and plays hard in her kindergarten classroom. I recommend these to all my friends.