Moms, what do we think of under shirts bodysuits for babies? Necessary or something of the past?

I don't use them. My baby runs on the warmer side, so he doesn't really need the extra layers.

My baby ONLY wears a onesie nothing more

Just a onesie. My son runs hot and gets super fussy if he is too warm, so an extra layer would be excessive and cause more issues.

I double up because babies cant regulate their body temperature very well I notice that even if her neck feels warm, her hands and feet are freezing. She also doesn't fuss like she is too hot or get flush and red in the cheeks. the only thing that makes her fussy is if she is wearing socks when she goes to bed that will sometimes make her fussy she likes to have her feet free unless she is in footsie pajamas or if she is too cold she will scream at me. But I think it depends on your baby. Mine really likes being warm .

I would use them, it's like a singlet and extra layer to keep warm.

never used them. my baby runs hot and i live in the desert she already gets too hot in just her pjs sometimes