I have the Kenai vest and run it under my jackets street wear included. It almost run too hot for me where I live in the 40's. 30's to upper 30's seems to be the sweet spot as mid layer. I didn't get to hunt this year but did plenty of hiking in it. It's worth the $165.Morning @pawlyb i did run it as a mid layer on a few days in October in to the 20s and got cold…….the majority of my time wearing the Kenai was as an outer layer to test durability, breath ability and the water resistance aspect…..for most would say comfort would be in to the 40s and 30s and once you get into the 20s you will need another insulating layer…in November I ran it over my super down pro into the low teens once I got to elevation as another insulating layer when sitting then wore as my out layer when moving…..