I also worry about this! expecially now since we are in tazmania on holidays... But i put Izzy in singlet 2growsuits, wrapped in blanket with 2blankets on top... and everything will be warm except her toes! (she's got cold toes like her mum ) also got heater on in the room... And i thinking that she's warm since she still settling into bed and sleeping a peaceful 7-8hours...