I have a 2018 F150 Lariat with 3.5 EcoBoost and tow package. My stated towing capacity is 13,200 lbs.and I am towing a 28' Airstream that weighs in loaded between 6,500 and 7,000 lbs. When towing I use "Tow / Haul" mode and keep my speed at 65 +/-. When towing at that speed the truck usually cruises in 8th gear turning a bit less than 2,000 RPM and it seldom downshifts unless climbing a pretty steep grade. I've noticed when I'm running for a while with a good bit of turbo boost (like climbing a long uphill grade) the temp gauge will move up to about the halfway mark or slightly to the right of halfway (nowhere near the "red") and the actual temp will begin to display above the gauge. The highest it ever seems to go is 230 and it only stays there for 10-15 seconds (or less) before dropping back down to where the gauge is normally (which is slightly to the left of the halfway point) and the temperature readout disappears at about 226. Ambient air temperature doesn't seem to be a factor but it just seems to me like the temperature should stay in the normal range all the time when I'm well within the towing capacity and running at moderate speeds.

I understand that running with turbo boost it's normal for the engine to run a bit hotter than when there is no (or minimal) turbo but Is this kind of temperature (226-230) considered "overheating" and is it possibly causing undue stress on the engine?
If this temperature is not good what can I do to fix the issue?

Thanks for your comments

 

230 is no problem. Above that, it's technically overheating but 245 is where you can risk damage.