Use BIOS/UEFI hardware monitor
Open Task Manager and check performance tools if available
Install a temperature app such as HWMonitor, Core Temp, HWiNFO, or SpeedFan
Check CPU temperature in Windows with manufacturer software
Check GPU temperature with NVIDIA GeForce Experience, AMD Adrenalin, or MSI Afterburner
Check laptop temperatures with OEM utilities like Dell SupportAssist, HP Command Center, or Lenovo Vantage
Use command-line tools if supported by your system
Check temperatures in Linux with sensors and lm-sensors
Check temperatures in macOS with third-party apps like iStat Menus or Macs Fan Control
Compare readings while idle and under load
Watch for unusually high temperatures during gaming or heavy tasks