Apple - MacBook Air CPU core PECI temperature

Here are some things to keep in mind for your streaming event.

• If the CPU gets too hot, the MacBook will throttle and reduce clock speed. That could result in dropped frames. Most of the time you will hardly notice the difference.

• iStat Menu has a utility to override fan speeds. In your case I would consider cranking up the fan to full speed during the streaming event, unless the noise is an issue.

• During the event put something underneath your MacBook so air can circulate below it. That doesn't do miracles but results in 1-2 degrees less and therefore less risk of throttling / dropped frames.

Macs have pretty sophisticated cooling design and CPU temperature is not the only aspect taken into account for controlling fan speed. I would suggest you do another dry run for 2-3 hours. If you don't have issues during that time 12 hours should work as well.