Last week while in the parks daily most all day and night I had no trouble till the last day then got blisters ONLY day I didn't wear medipeds with cool max. I had Dr Shols socks for my last day. Same shoes only thing that changed was the brand of socks I was wearing I am pretty sure it was that soft terry cloth stuff on the Dr shols socks that caused my blisters. I've had trouble with the terry cloth lined socks in the past. I felt hot spots almost immediately after entering the parks turning the socks inside out helped some but by that time I had the blisters. Of course this is the only day all week I didn't go back to the room mid day and was in the parks from 8:30 am till 3 am. At least the blisters didn't get worse after I turned the socks inside out.