The car in question is honda civic 2005 with d17a2 engine with cvt transmission.
Problem.
The car heats up when climbing steep slopes of like babusar top from chillas side(there are many other examples where this has happened like where there was just steep slope and elevation was like 5/6000 feets) slow speed of like 10/15 kmph and rpms between 2000/2500. Some coolant shoots out from reservoir bottle when this is happening. I have noticed the fan doesn't turn on when the temperature gauge is going up. Fans turns on eventually at some point though automatically. If i turn the ac on in such scenario temperature remains normal.
While driving in normal conditions like in cities or at highways or at idle temperature gauge never cross the half mark.
Colant in the radiator looks good and engine oil is also fine and there is no smoke as well so it could not be head gasket.
Mechanics after checking everything is suggesting to have an extra switch in cabin to turn the fans on manually to avoid overheating but that's not the solution.
