Doing an overnight brisket (14lb) on my large. For some reason the temp has spiked twice over 280. Both times I've had to shut off the flow on the top and bottom dampers and start over. I'm keeping the air flow on both dampers at a minimal. The spikes happened both times after I opened the dome, probably increasing the air flow to the embers. What is the best way to lower and stabilize the heat, getting nervous because this guy is cooking quicker the any other ones that I have done. At two and a half hours in I'm at 133. Hopefully this won't be a sleepless night.