sleeping with hat

Hi mommies... 
are your LOs still sleeping with a hat on? My LO is gonna be 8 weeks tomorrow and has been moving around so much in his bassinet the hat keeps falling off at night. The room temperature is usually around 74 degrees. I don't want him to be cold but when he's sleeping so peacefully I don't want to wake him up by moving his head around to put the hat back on.