The only problem I've had with Sorbothanes is that when my feet get really hot, especially when walking on tarmac, the underside of my feet can feel like they are on fire. When this happens I stop, take them out, turn my socks inside out, cool my feet with water, dry them, put socks back on, put in a an old pair of Keen insoles (left over from my old Keen Targee boots) and then stroll on! Rarely fails!