thanks for the positive info. I'm in no need of Vaseline myself as my pens are adequate for my birds and I do live in a relatively cold climate for the winter season. And as @GodofPecking reiterated there are certainly plenty of alternatives to simply using Vaseline. The alternatives as well as pen structure can be addressed without pretension and I feel would be a more appropriate focus for this thread.At the very most it's a minimal bandaid fix to a bigger problem... It only has a marginal effect on human skin in the cold and the reason it has that effect is that we sweat and it helps prevent some evaporation, chickens don't sweat so that effect is nil... What it might help with is providing a very marginal barrier for water drops that might land on the exposed skin... But, if you have water drops forming you have bigger issues that need adressing... It also might provide some minute insulation value and possibly shed melted snow that lands on the skin... At the end of the day it likely won't hurt anything but I doubt it has much quantitative benefit at the end of the day...
Remember if you use it on the chickens and they don't get frostbite, correlation does not necessary equal causation...
Attimus