You're right about heat being bad, but that 100 degree figure is actually pretty low... it's celsius, not fahrenheit. Battery University says 100C, which is 212F. Still, even lower heat hurts them over time. Blocked vents will definitely get things hot enough to do damage. Good on you for cleaning it out and telling them.

My last brisket at 225 felt like watching paint dry for a day.

So @jade_lane, what kind of saw were you using when you figured out that upside-down trick?