Having started doing some serious training for the Para's 10 next month I've started running in boots, as well as tabbing around the Beacons. Problem is I'm getting heel blisters like a Saturday night slapper! I'm currently wearing Lowa Combat GTX's with Bridgedale medium thickness socks. I wear this combination on work all day (and no, I'm not an office jockey) and it gives me no grief at all, even on long periods of foot patrol, but as soon as I start speeding up/climbing/carrying weight they start rubbing like buggery. Any ideas?