One of the first things I would try is to clean the rad and all the pipework out on the water system side. Secondly I would check the water pump operation. Thirdly check the heater matrix inside the car to see if it is blocked.

The main issue with high temps is a block in the system which means the water does not flow properly and just sits in the block.

You could do with checking the thermostat operation as well as these can lock and restrict or stop the water flowing.

With the higher ambient temperatures you are going to see a significant rise in the operating temperature of the engine anyway.

I would remove all pipes, check and clean all. replace thermostat (you can remove but can cause cold start issues) check water pump operation and wire up the fan to a switch.

If you still have problems you may want to check the head or the block for cracks and debris or you may have restrictions in the head gasket waterways.

If you are blowing header tanks it would suggest pressurisation of the system which would point to a head gasket issue. You can get this tested quite easily without removal of the head. I have forgotten what it is called but I think someone will have an idea and post on here.

I hope it helps.