These are cute, but waaaay too big for my normal-sized daughter. It's also pretty comical that they have "thumbs" when her whole hand could almost fit in the thumb spot. Basically these are cute mittens to look at, but not very functional (at least for little infants). They might be perfect for toddlers.
I ordered the large and they fit my almost 3 year old daughter well. She claims that her hands were not cold in them, although she would also say that just because she wants to stay outside. But her hands were warm when I took the mittens off after she came inside. They are very soft and easy to put on and take off. And they come in the best colors!
These are great. We used them all winter with my 1 - 1 1/2 year old. They were easy to put on him, even though he was to young to help and they allowed him to still grab stuff which eliminated tantrums. The lining comes out of the thumb when you take them off which is the only downside. It is however easily stuffed back in. To bad Patagonia or MJ doesn't make a baby friendly clip for them so they don't get lost.