I assume you are referring to the Electric Angel, or EA
mod. If this mechanical
mod is what you have, a hot button is likely caused by too much resistance in the switch components. When it happens check the coil resistance again to make sure it didn't short (unlikely with a insulated ceramic wick, but just to make sure). Have a look
at this thread where Rolygate answers another EA mod hot button question for more information. Mechanical mods need maintenance to keep the contact points free of oxidation and low in resistance. You can clean the contact points in the switch with fine sandpaper and use a small amount of conductive lube like Noalox on threads and contacts to slow down oxidation. Search on ECF and Google for a lot more information on this.
If it were me and I was having trouble with a Electric Angel I would also seriously consider contacting the manufacturer for advice.