Side sleeping

Em

My little boy is 4 weeks old and this morning when I put him back down to sleep he managed to turn himself on his side - twice. I put him down in his crib on his back.

Caveat: he has a heat rash so we put him to bed in just a pajama last night. And we typically swaddle his arms out (when we used a swaddle) since he loves having his arms free.

Anyone else have this or know how we can stop it from happening?