While I have managed to avoid blisters myself one or two usually show up on someone during the course of a Troop backpacking trip. Dr. Paul Auerbach has posted a very comprehensive treatise on preventing and treating foot blisters:
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Basic Blister Treatment (for intact blisters):
1) Cut moleskin (or a basic blister care product) into a donut of diameter ½ inch to 1/3 inch around the blister. The blister should fit inside the hole in the donut.
2) Place a patch of Spenco 2nd Skin in the donut hole directly over the blister.
3) Cover the moleskin donut and patch with benzoin and tape. Note that this “traditional” moleskin/donut treatment may cause further pressure points either directly under the moleskin or by transferring pressure and subsequent increased friction to the opposite side of the foot.
Basic Blister Draining:
1) Cleanse both the blister skin and a safety pin with an alcohol pad (the diameter of a safety pin is larger than that of a sewing needle to allow continuous drainage, yet not so large as to risk de-roofing the blister).
2) Puncture the blister with the pin at several points at the margin of the blister (generally on the outside of the foot), rather than via one large hole. This will allow natural foot pressure to continually squeeze out fluid, limiting the risk of de-roofing the blister.
3) Gently push out fluid with your fingers.
4) Blot away the expressed fluid.
5) Cover the drained blister with paper tape (protects the blister roof when any other overlying tape is removed).
6) Cover the paper tape with benzoin, then with shaped adhesive tape. All tape should have trimmed and rounded edges to minimize “dog ears” and
7) Reaccumulated fluid can be drained through an intact bandage.
Open and Torn Blister Treatment:
1) Using small scissors or another sharp object, carefully de-roof the blister, completely trimming off the dead skin.
2) Place Spenco 2nd Skin on raw skin.
3) Cover the Spenco 2nd Skin with paper tape.
4) Apply a benzoin coating.
5) Cover with Elastikon or another tape product.Toe Blister:1) Drain the blister with an alcohol-cleansed safety pin.
2) Use one piece of Micropore tape to encircle the (leaving the torn tape end at the dorsum of the foot to avoid irritating neighboring toes).
3) Pinch closed the tape.
4)Trim sharp edges or wrinkles in the tape. Avoid cloth tape or Elastikon on the toes, as the abrasive nature of these tape varieties may cause blisters on adjacent toes.