Special equipment: 4 packs 4-inch-square wound dressing pads, such as Melolin 4 packs 4 3/4-inch-square adhesive wound dressing
Combine the chiles, coconut oil and mustard powder in a saucepan. Cover to keep in the vapor and gently heat for 2 minutes. Let cool with the lid on. Put the chile mixture into muslin over a sieve and squeeze out the oil into a bowl below. Place the oil back into the saucepan and return to the heat. Add the beeswax to the oil and heat very gently until dissolved; this will take less than 2 minutes. Remove from the heat. Soak the dressing pads in the oil mixture while it's still hot. When they are saturated, remove the pads and let stand until set on greaseproof paper, 10 minutes. Once set and dry, the pads can be layered on top of each other, wrapped in plastic and stored in the refrigerator until needed. Place a pad on an adhesive wound dressing, then apply to the affected area. Keep the area warm (by covering with a blanket, for example) and leave on for 30 minutes to 1 hour. The plasters will keep for 1 year in the refrigerator.