How to get Isaac to sleep

Jake and I took the kids to Kohl's on Saturday. We let them pick out something to buy and got some Christmas shopping done. Isaac got to pick out some new jammies since his winter pajamas from last year were way to small. He picked out a two pack of toy story pajamas. One set is Buzz Lightyear and the other set is Woody. Last night he went to bed in Buzz Lightyear pajamas, and this morning when he go up he was in his Woody pajamas. I asked him what happened during the night and he said, "My Buzz Lightyear jammies were making me too hot so I put on the Woody jammies." Not sure when this happened because he didn't wake us up during the jammie switch. I thought his response was pretty funny especially since the jammies are exactly the same weight, just different patterns.