If you live in the South, I suspect you have a baby carrier that has a panel of solarveil, kool nit, mesh or some other material to keep it cool. When Winter comes, that panel is not so useful. You could buy another carrier, I'm sure that would be more fun, or you could crochet a cover. The reason I crocheted one (in addition to my fleece one) is that it gives it that "sweater" look too, which I think looks nicer at mass.
This is sized for a toddler kinderpack so will be a bit big on a sandard kinderpack but will still work, it should work on other structured carriers and mei tai as well, the angles just may not meet up exactly. This pattern can be adjusted for different sizes by adjusting the starting chain. I personally would make the toddler size in case you ever have to get a bigger carrier, it would still be usable.
approximately 10 oz worsted weight yarn, I used Simply Soft because that's what I had on hand
H hook, I crochet loose so be sure to check gauge
gauge 2"=8sc by 7 rows
1) sc in 3rd chain from hook and in each chain across ch 1 turn (72 sc)
2) sc in bl only across ch 1 turn (72 sc)
3) sc in each chain across ch 1 turn (72 sc)
4, 6, 8, 10, 12, 14) repeat row 2
5, 7, 9, 11, 13) repeat row 3
14-68) sc in each sc across ch 1 turn
69-80) sc dec over first 2 sc, sc 68, sc dc over last 2 sc, ch 1 turn (row 80 is 48 sc)
81) sc in bl only across (48 sc)
82-112) sc in each sc across ch 1 (48 sc)
113-123, odd rows) 2 sc in first stitch, sc 46, 2 sc in last stitch, ch 1 turn (row 123 60 sc)
94-122, even rows) sc in each sc across sc 1 turn
124) sc 4, dc 23, sc 6, dc 23, sc 4, ch 1 turn
125) repeat 124
126) sc 5, dc 21, sc 8, dc 21, sc 5, ch 1 turn
127) sc 6, dc 19, sc 10, dc 19, sc 6. finish off.
fold upper portion in half and stitch closed from the beginning of row 124 up and across the top and down the middle until stitched closed to form hood.
On wrong side attach yarn at bottom corner to the bottom of first stitch of foundation chain, ch 20, sl st in first fl of row 14, sl in next bl of row 14, sc down the ch 20, sl st into bottom of next stitch in foundation row. sl st in next stitch in foundation row. sc in each sc in the ch 20. sl st into next fl of row 14, finish off. Repeat for opposite corner.
Sl stitch into the first fl of row 81, ch 15, sl st around the first stitch from row 69, sl st around next stitch, sc in each ch 15, sl st into the next fl of row 81, sl st into the next fl of row 81, sc in each sc from the ch 15, sl st around next st of row 69, finish off. Repeat for opposite side.
The waist strap loops are loose allowing the bottom to adjust to seat darts if using on a carrier like the Kinderpack or the stretch of a carrier like the stay cool. It is also wider at the waist strap to make up for the seat darts or stretch so it still covers everything in the middle of the carrier. The shoulder strap loops are pretty snug but will stretch to accomodate. It needs to be snug to support the hood.
You could also add similiar loops for the webbing to hold it in place even better. You could also add loops to the hood for the straps of your hood to slip through so you could still use the hood for support.