What should baby sleep in?

My boy has his 4 month shots today and has a temperature of 37.5. He usually sleeps in a long sleeve bodysuit and a 1.5 tog sleepsack. I don’t want him to overheat if he already has a temp.

I’ve got 2 bedroom windows open and the temperature egg currently says it’s 23 degrees in the room. My bedroom runs warm, it’s always always hot in here.

Will he be alright just wearing a long sleeve bodysuit to bed or will he get cold?