Doesn't really matter if the baby's on the inside or the outside, does it? From Cathy of Chief Family Officer:
This seems like a pretty obvious idea so it may have come up before, but it was new to me so I just posted it on my own blog and am sharing in case you want to pass it along to your readers as well. With the change in weather, I pulled out my maternity coat to wear when I have my baby in a front carrier. I am able to zip the coat up so he's nice and cozy as we walk outside.