I guess I'm fortunate as I do not sweat much at all. My lower back is about the only issue I have. I start cold, I'm amazed at other's at the trailhead in full Gore-Tex suits, heavy mitts balaclavas. I typically wear long sleeve base layer under a softshell vest, to start, if it's to cold for that, my Patagonia Puff, but that's rare. I almost never hike uphill in a shell, that is to hard to regulate for me. At treeline, I'll switch out my vest for my Puff jacket but before I do, I strip off my LS base and replace it with a SS base, as my jacket is to hot with a long sleeve shirt. If it's windy, I will go to my shell to cut the wind. If it's epic cold, I have a Parka that I can wear over anything, I bought it to wear over all my layers, just in case, as I do not carry any bivi gear. One thing to consider is headwear to regulate your overall temp. I carry a silk weight balaclava, a beanie, a heavy balaclava and will use them according to temps, if your overheating, try no hat to vent, as the heat your generating will fly off your head like a chimney.