I'm on the hunt for the coolest carrier for a newborn - 3 months for summer and would love suggestions. We already have an Ergo, Close Carrier and Kleinsmekker mei tai, but they are all either fairly structured or just too warm. We don't drive, so it needs to be something baby could be comfortable in for walks (train station 15 min walk), public transport etc. My preference is for a mei tai, I loved it with DD when she was little, but not sure if there are materials cool enough. Any suggestions for brands etc that are great summer carriers?