16 week immunisations

C
Hi all, 
My son is 18 weeks but had his jabs today as he was behind due to being in hospital at 12 weeks. Just been on the phone to 111, as he got a temp of 39.2 but couldn't have more calpol till 22:45... Anyway they gave us some tips and we've got it down and a GP is calling me back at some point. But my question is, what do I put him down to sleep for the night in (not that I'm expecting him to sleep through), but usually he wears a vest, baby grow and a sleeping bag (winter 2.5 tog) I'm guessing this will be too much... I do have a summer sleeping back which is 1 tog and would prefer to have him in 1 as he settles better. So do I put him in just a vest which he is now in his usual sleeping bag or put him in a vest and baby grow but just his summer sleeping bag? Any thoughts or advice would be lovely! FTM and winging it every day! Thank you x