Driving uphill Overheating issues

I live in Vegas where temperatures often exceed 100°F. My 2012 Toyota Prius tends to overheat when driving uphill. The overheating light turns on, and my scanner shows the temperature rising to 220°F. I have the AC running and am driving at around 75 mph during this test.

I replaced the water pump and cleaned the entire EGR and air intake system. This helped somewhat, but the temperature still reaches 214°F, and the overheating light continues to activate.

Are there any aftermarket modifications I could consider? For example, an engine oil cooler, an all-aluminum and wider radiator, or adding a secondary radiator (such as a large transmission cooler)?

 

This is what I think. The upper radiator hose is positioned in the middle of the radiator, which can be a design flaw. In this setup, the area where coolant flows quickly through the radiator is smaller compared to a traditional radiator where the upper hose is located at the top. In a traditional design, coolant enters the radiator from the top, ensuring it is evenly distributed across the entire surface, which improves cooling efficiency. However, with the hose in the middle, the flow may be less efficient, leading to potential cooling issues.

 

It doesn't even matter what I replace, even if this car was brand new. It would still overheat because it has a design flaw that causes inefficient cooling.