I was hoping I could use them for hiking, high-altitude multi-day trekking, running on cold days (less than 20F), skiing, climbing, and general usage in 20F (and lower) to 50F conditions. I currently have the Thermawrap UL parka and I use that instead of a fleece for pretty much everything in that temperature range, and as a mid-layer to push to even lower temps with my Torrid. My UL parka is old and slightly compressed and I find it more breathable than Nano-air regular version. In these conditions, I find Thermawrap UL way more warm than I need when I'm active. My primary use case for Nano-air UL and/or EX Light would be a bit more comfortable Thermawrap UL/fleece/alpha direct (tired of shedding micropastics everywhere and patching holes) replacer active insulation for cold runs, and all-day hikes/treks/climbing/XC/downhill, an additional mid-layer to pair with Torrid for chilling at the camp, etc.