So one of my 20-month-old twins seems to just hate blankets. Where we live, it's warm when they go to sleep but gets pretty chilly around 2-3am. So I've been putting them in their normal pj's but then go in in the middle of the night and put a blanket over them. One seems to get it just fine, goes to sleep w/ a blankie and will often have it already covering his legs. The other will wake up at some point, scream and throw the blanket out of the bed, but then scream because he's cold. I mean, I assume that's why he's screaming as his legs & feet feel freezing. We've done sleep sacks until the start of this summer, but I think they are too big for the biggest size. Should I try to find another sleep sack, or insist on the blanket? Is this even a "thing," this blanket-hating habit?