I occasionally take my 4 year old for short rides in the field behind my home. Would like to get him a helmet but really no where to go and try them on around here (IA). I would think a full face would fog up on him and be awkward so leaning towards open face and goggles. Always warm when I'd be taking him out and generally less than 20 miles per hour. This way he could use it in the summer as well on 4 wheelers and what not. I don't want to have too much wrapped up in one as he will probably out grow it within a couple years. Any recommendations on reasonably priced set ups with good fitting guides/return policies, etc.