Clean dust from heatsink, fans, vents, and filters
Reseat the CPU cooler
Replace old thermal paste
Improve case airflow
Add or reposition case fans
Increase fan speed with BIOS or software
Lower CPU voltage
Reduce CPU boost settings
Limit maximum CPU performance
Close unnecessary background programs
Remove overclocking
Keep the PC in a cooler room
Ensure the case has enough clearance
Use a better CPU cooler
Check that all fans are spinning properly
Update BIOS and chipset drivers
Replace failing fans or pumps
Use a laptop cooling pad for laptops