Ditto what a couple folks above have said. After removing the seeds & veins, soak in any lemon-lime soda (sprite, sierra mist, etc). The diet ones work just as well. Most of the time I only let them soak 10-15 mins. This leaves a slight amount of heat. If I want almost no heat at all, then 30 mins minimum.
Also, slow cooking, 2+ hours at 225, will also reduce a lot of the heat.