Learn how to read CPU temperatures on Linux and act before heat becomes a problem. 27.11.2025 | reading time: 2 min When a server runs hot, an admin must know which sensor to trust and what the numbers mean; this short guide shows how to read CPU thermal info from lm-sensors and the kernel's sysfs so he can verify temperatures and react quickly. Read sensors and sysfs Try these commands to get immediate readings: ```bash $ sensors coretemp-isa-0000 Adapter: ISA adapter Package id 0: +48.0°C (high = +80.0°C, crit = +100.0°C) Core 0: +45.0°C (high = +80.0°C, crit = +100.0°C) Core 1: +44.0°C (high = +80.0°C, crit = +100.0°C) $ cat /sys/class/thermal/thermal_zone0/temp 48000 ``` The `sensors` output gives human-friendly degrees, while the sysfs file reports millidegrees; divide by 1000 to compare. Watch and log continuously Monitor live with `watch -n 1 sensors` or collect for analysis by writing a small loop that reads `/sys/class/thermal/*/temp` and timestamps values; logging lets him correlate temperature spikes with workload and spot thermal throttling before hardware damage. Important details to know Sensor names vary by platform: "Package" might be the whole CPU, "Core" per thread or core; thermal zones don't always map one-to-one to cores; check high and crit thresholds shown by `sensors` and prefer sysfs on embedded boards like Raspberry Pi where `vcgencmd measure_temp` may be available. Complementary tools Use `s-tui` for an interactive terminal UI with temperature and frequency graphs, `thermald` to help control cooling policy on supported hardware, and `i7z` to inspect Intel core states and per-core temps on older CPUs. Final step Temperature checks are quick and decisive: when a reading looks wrong, reproduce the load, cross-check another sensor, and act — change cooling, adjust fan curves, or schedule maintenance; deepen your Linux skills and consider certifying with CompTIA Linux+ or LPIC-1 using intensive exam prep at bitsandbytes.academy. Join Bits & Bytes Academy First class LINUX exam preparation. utilities troubleshooting processes
