What to wear under wallaboo footmuff?!

[Tangointhenight1]

Hey I have bought 2 wallaboo footmuffs for our twin girls who are 5 months old with the intention of using them on their buggy and also car seats when out and about. But what do I dress them in?
It says to be used in place of a coat or pramsuits but worried to just put them in baby gros (which is what they live in atm!)As they may get cold. What do you put your baby in underneath to make sure they are warm in winter? First time mum so bit anxious about it! Thanks for any advice :)

Just a vest and babygrow or what ever outfit they are wearing that day. The point of having it is that you don't need to have anything else underneath the car seat straps meaning they are properly fitted and won't compress, as a coat would, in the event of an accident. You'll need to open it when you go indoors/have the heating on in the car as they'll get too hot.

Thanks for the reply, I'm new and not sure how to see replies to my posts!

I would add a thick cardigan over babygrow. Plus hat and scarf, and mittens.