I live in the desert and it get to 118 in the summer. I don't know how many times the baby just didn't want to go in the car seat because it was too hot. A car-seat sun shade keeps the seat at a comfortable 69 degrees.
If I had this in the hospital the first time, I might have avoided that meltdown! (for "kangaroo care" in the hospital with a newborn) Halter Strap Kangaroo Tube. Won't need this for quite a while, but someday I'll be glad I pinned it :)