The vital organ.

There is a heat that wriggles into your heart, tugs the arteries, boils the blood, sends it in sizzling shock waves through your entire body. It blackens the vital organ and turns it to ash until that steady whomp of blood fizzles and pools down into your feet. This inaction will kill you, is what I'm saying. Life is circling wraith-like around and around and around your chest and you are dying. You're dying! Every single day! You with your jaw set and your eyes firm, you march on toward that steady death. And even when you get there, when the hole opens up and swallows you completely, nothing will stop that wide O of surprise in your eyes, shaping your mouth. Nothing will stop that sharp, sudden regret when you go.