Overheating during cam break in

I always install a restrictor plate in the stat-house, and a direct-drive fan.
And when it fires up on fast idle, I check the oil-pressure gauge while tugging on the dizzy to maximize the rpm. Adjust the rpm.Check for leaks.Relax a bit.
Check the O/P,Check for leaks,Check the temp.,Relax.
Repeat
At 2500 there should be massive flow through the rad with the direct drive fan.
That's what I do.
But yeah, I keep the box-fans handy, and running water, and a fire-extinguisher, too.And I fire-up outside; I may be brave, but I'm not foolish.............I learned some stuff along the way.
All it takes is a bit of a fuel leak and an errant spark to ruin your car,your garage, or your life. You know, we take gasoline so totally for-granted in our everyday lives, it's surprising we don't hear about more tragedies than we do. That stuff is just looking for any excuse to burn or explode.And when it goes,look out!
Yeah, I have done some stupid stuff..................But I made it to age 63 now...................and my buildings are still standing.