Q: MacBook Air overheats & drops AirPlay mirroring

My MacBook Air has recently been unable to maintain AirPlay mirroring sessions with either of the Apple TVs at work. I suspect it's automatically stopping the AirPlay mirroring, because the CPU core temperature spikes to about 98°C and the fan runs at full blast, about 6000rpm. (I'm using Macs Fan Control.) It can last about 60 seconds before

It's not unusual for the temperature go way up high other times, but I haven't been able to isolate why. Even uninstalling Flash didn't help. Typical temp is 60-70°C.

Is my hardware just deteriorating? Any ideas?

MacBook Air (11-inch, Mid 2011)

OS X Yosemite 10.10.2 (14C109)

1.8 GHz Intel Core i7

4 GB 1333 MHz DDR3

250GB SSD

Intel HD Graphics 3000 384 MB