You're going to need to provide more information if you're looking for help.
Also, what do you mean by "gets hot under load" ? What are the temperatures at idle and at load?
If your radiator fan is blowing hot air out of the PC case to cool the radiator, you might need to reverse the fan and install it so it blows cooler outside room air over the radiator - and unfortunately into the PC case where it will heat up the HDD/SSD, GPU card, DRAM, etc.
It's also worth checking the CPU vcore voltage under full load. If this is excessive it will cause the CPU to run hotter than normal. Applets like OCCT can record the vcore voltage, CPU frequency, etc. to help diagnose these types of issues.