Torched

First, you feel uncomfortably hot. But it's no use turning up the air conditioning or reaching for a long, cool drink. Whatever you do, the temperature inside you keeps rising. And rising. Soon you're in agony beyond your wildest nightmares as your whole body is engulfed in searing, unbearable heat. You go mad briefly with the pain. Then, with luck, you black out. If your luck holds, you're dead soon after.
Very dead. But your involuntary cremation continues. Your blood boils in your veins for a few seconds - before it bursts them. As your tortured corpse dries out from the horror-heat inside it, your skin blisters, pops, bursts - and then flares into scorching flame fueled by your own melding body-fat. Clouds of choking, greasy smoke join the searing blaze consuming what's left of you. You have become your own funeral pyre...