Nervous about potential overfire... any advice?

I'm currently getting a lesson in the effect of increased draft due to low outside temps. My IR thermometer says the Matrix insert is a bit over 800F right now, less than an hour after loading it for the night. I closed down the air when it was much cooler, but the temp has continued climbing anyhow. What does one do in this situation?

Edit: to clarify, the temp. was measured on top of firebox, through the air vent.

Eh, maybe not so bad... just in the few minutes since I posted this, it seems to have peaked and come down a bit. The IR is now reading around 775, which is a little less intimidating than the 815 it was reading before.

That is normal for it to burn off the nasties gassing out of the splits. It will level out and find her cruising temp. Loading larger splits will help this some.

Thanks, Hogwildz. I'm surprised how quickly it's cooling down without my doing anything. It has dropped 100 degrees in 15 minutes -- now just over 700. Nothing is glowing, and I don't detect any evidence of damage, but somehow I don't think this load is going to last through the night.

Thanks for the reassurance, begreen. It's 4AM and the stovetop is at 300F with a prodigious bed of coals. Not so bad, really.

Try raking the coals forward and laying a couple splits in the back on the fire brick then load on to the coals as you normally would. , this will help prevent the whole load from off gassing all at once.

That's a good thought for these extremely cold nights, Ed. I always rake the coals forward, but last night's load was N-S, which may have compounded the problem.