Just got my khaki Gila hoodie and gaiter. They were sitting in my mail box in the sun; about 100 today (nice spring day.
Since they were baking in the sun while in the mail box, they were initially hot to the touch when I opened the package. After a few moments (less than a minute actually), they did begin to feel cool to the touch.
The material feels similar to the Sitka Redline (athletic lineup). The material is significantly softer and smoother than the Enduro, Peloton 118 and Ultra Merino 125. It is smoother and thicker than the old Tiburon. It is closer to their Training Tech shirt but a bit softer and thicker.
I would not wear the Gila as a standalone item and I would not bust brush with it. I would wear the Enduro, Peloton, or the Ultra merino as a primary shirt. I would treat the Gila like insulation; wear it while stationary and remove it when it is time to move.
It is supposed to range from 113-117 degrees coming up so I should be able to do some casual testing.