If you do not have SShack, the warning is meaningless, as you either lose instantly via sudden-death or you are unaffected entirely. The warning does not at all trigger in any kind of timely manner. If you *DO* have sshack, the warning means you have 3 hours or so to do something about it, which should be plenty.
Yes, I have sshack. I just sent him off on the bus, as I got the warning just as it hit 8am, and when he got home from school, his temp was back to normal.