Temp too high ?

I pose this scenario to those who have engines that run too hot [ whether they are actually too hot or the owner is just worried about it ]. Especially pertinent with 4.10 gears which will have high engine rpms on the freeway.
"The engine produces twice as many power strokes [ that create heat ] at 4000 rpm as it does at 2000 rpm, but it has no increase in volume of coolant & radiator size to cope with the doubling of the power strokes"