Military had the right idea, but they messed up. I was always having issues with issue socks, until I figured out they were only half wool, and the other half was cotton. That cotton kept the sweat right against your feet. When I switched to 100% wool socks (remember the old white sweat sock), and started washing my feet twice a day, the jungle rot went away. For the last few years, I've been wearing Costco wool socks year round. They are surprisingly good for what they cost.