How to use sun hoody in a layering system

Are they really dipping garments in sugar substitute?

Not dipping but . . .

"Sol Cool uses Icefil technology to keep you cool and comfortable in hot climates. The compound Xylitol, which occurs naturally in the birch tree, is woven into fabric. When it comes into contact with moisture like sweat, it reacts, creating a cooling sensation similar to mint gum. Xylitol can cool the skin surface up to 5°F"

huh. Learn something everyday. But don't let your pets lick your shirt – the one I think I do know about Xylitol is that it's said to be toxic to dogs.

I literally just licked/chewed on my hoody…. Didn't taste sweet at all. My tongue does feel a little cooling sensation though. Like mint….but without the mint flavor. Weird.
Maybe that will subside after the first wash?
STOOPID!!!! Nevermind I'm drinking ginger tea right now….can't accurately assess that now since my whole mouth is spicy gingery feeling now.

Anywho….anyone use this in their layering system? I'm guessing I'll need to separate it from my skin with another base layer when it's cold out?

I would use it like a mid layer. If you are hiking in weather hot enough to want a sun hoody, it seems you could just take the hoody for your mid layer (wild assumption).