Use BIOS/UEFI hardware monitor
Use Windows Task Manager or vendor utilities
Use macOS Activity Monitor plus third-party apps
Use Linux sensors command
Use motherboard software from the manufacturer
Use CPU monitoring tools like HWMonitor, Core Temp, HWiNFO, or Open Hardware Monitor
Check temperatures in your laptop or desktop fan-control app
Read the CPU temperature in your system’s firmware settings
Use command-line tools on supported systems
Compare idle and load temperatures while running a stress test