First, download and install HWinfo64 from
https://www.hwinfo.com/download.php, screenshot or take the CPU temperature readings without load and during load, so that we can see how hot your PC is running and to help you better.
Some free or cheap ways to reduce the heat before you consider liquid cooling, mineral oil cooling, etc...
(1) Remove the dust from the internal components (CPU fan, casing fans, etc...) in your PC. Switch off the power and remove the power cord first. Don't use a vacuum cleaner on your motherboard as the static charge can kill the components.
(2) Check whether your CPU cooler fan is properly seated and CPU thermal paste had dried or not. If the CPU cooler fan is improperly seated or the thermal paste had dried, then remove the existing thermal paste and reapply before installing the CPU cooler fan.
(3) Reorganize or manage your internal cables so that airflow is better.
(4) Adding more casing fans and installing a better CPU cooler fan.
(5) Check whether all your CPU cooler fans and casing fans are working.