Hi there and thanks for sharing your question with us at HCM. It seems as though the red spot you have described is a developing blister. Sadly, heel blisters can occur even with the highest quality footwear. As you are about to be deployed, I think understanding the mechanics behind the development of a heel blister can help, given that you have experienced them once before. As we walk or run, the heel bone normally gets pulled up by the Achilles tendon. However, once the calf tendons get tight with prolonged usage (with prolonged running / walking), the heel bone is lifted even sooner and with more force. All you need is extra friction (which is provided by socks and the shoe lining) to cause shearing of the soft tissue and skin overlying the heel bone. This repetitive shearing results in micro-tears beneath the skin, eventually resulting in a painful, fluid-filled cavity (blister). Some individuals are still blister-prone despite providing themselves with the most comfortable and finest footwear. Here are a few strategies used by my blister-prone patients: 1. Minimise friction by keeping your foot firmly in your shoe (do not allow your heel free movement as you walk or run) - lace up fully. Of course, ensure that your socks and shoes fit you well. 2. Stretch the calves properly (30 seconds) before and after exertion 3. I understand that you have tried moleskin - consider trying a patch that sticks to the inside of the shoe like an ENGO patch - it will save you time (considering you are in the military). With regard to the current blister, do not remove the roof - this leaves the blister sterile and allows it to heal properly. If it has burst, remove the dead skin with a sterile pair of scissors, clean the wound and have it dressed properly. Check it daily to pick up any infection early. Hope this helps. Good luck on your deployment. Dr Shabnam