[smo]

I don't have a "next line" for the danger zone, it's just marked off with an orange line on top that drops down denoting an area at the top of the gauge. Anyway, that sounds pretty normal on hot days. I've seen mine get above it a few times but the fans kick on when it gets pretty close to the bottom of the top most line.

It could also just be a simple grounding issue and you are just noticing the temperature now that it is hot outside. I've noticed in my car that prior to repairing my odo gear that the gauge would read near the second line frequently in warmer weather. Since I've put the cluster back in and reseated things I haven't seen it do this. We are just getting into the warmer weather though.

Additionally I've noticed that the gauge flicks around sometimes with the turn signal blink frequency. If the a/c is on the gauge reads higher. When I have the lights on the gauge moves up. When I stand on the brake the gauge moves up. At night at a dead stop with my turn signal on you'd think the engine was going to blow.

So I guess my point is. Check out the grounding around your cluster before worrying about the harder stuff. Also, if it drops almost immediately when you start moving again then that is normal AFAIK.