What do I need to do if it says high temperature?

Hello, Is that message coming from the weather app on the navigation unit, or is your engine temperature gauge showing the engine is past the center point? You would do well to get it in for it's normal maintenance, as normal maintenance is a great predictor of longevity. As for the high temperature notification, I have a sneaking suspicion it is telling you that the weather is brutally hot in the Texas sun (probably 90 degrees and up) You would do well to check the owners manual for all the different messages it gives you.