If you do a Google search on what baby should wear at night, it will tell you what to put them in for the different temperatures. Our room was 24 degrees, so he's slept in a footless bodysuit no vest with a 0.5 tog sleeping bag
I think it’s really hard. I put my little one to bed in a short sleeved vest and sleep suit and he was cold even though the room was showing as 23. Like a guessing game minefield each night here
I think I stopped putting a vest under his sleep suits at 20/21 degrees, it’s currently 24.5 and he’s in a legless sleep suit with no vest and a thin summer bag
My daughter is dressed in exactly the same clothes and the room says 24degrees. I’m constantly checking if she’s hot so I’ll know when to take out the sleep suit. I’m interested in what others will have to say.