How to keep newborn warm at night ?

So I’m having my baby next week and the one thing I can’t seem to find an answer to is how should I put him to bed? Our rooms tends to be cold because we can’t sleep at all if it’s too hot and I was planning on swaddling him but I’m not sure if that’s enough to keep him warm. Our apartment doesn’t have a thermostat it’s just a switch that turns the ac on so I can’t monitor the temp. So what else can I do to make sure he stays warm at night? I know if I put a loose blanket over the risk of sids is higher so what do you experienced mothers suggest?