How? What the Hell, Cas? [Does he truly not remember? Maybe it's something like whatever amnesia he had over this place.] Turns out, killing a Leviathan with a God weapon has consequences. I boned Dick and he boned us. Not the good kind of boning. The kind that gets your ass thrown into Purgatory where every monster there wants to chew out your liver.

[He could feel Cas' shaking through their contact on his shoulders. This made Dean frown, concern etching his features.]

You're cold. You're shaking. You don't shake.

[Dean reached into his pocket for his final match and, without hesitation, struck it, holding it out to Castiel.]

Cas, [His tone was firm.] why are you cold?