Coolant warning on up hill?

[Dandan]

Hi purchased my Karoq recently 2019 2.0 Scout

On the motorway this morning when going up two inclines the coolant temperature rose significantly and went into red, but when I got on the flat and/or down hill temp went back to 90c.

Could this just be coolant levels?
What coolant would you recommend for the Karoq?

[Mr Happy]

you can use the coolant as sold by Audi Skoda Seat and VW and it is less than a tenner