Temperatures sensors can be queried with utils in the raspberrypi-firmware-tools package. The RPi offers a sensor on the BCM2835 SoC (CPU/GPU). This is a simple bash script which you can copy paste on raspberry pi. Create a new file with command nano CPUstat.sh. Copy the below code and paste it into that file.

	#!/bin/bash
	cpu_temp=$(cat /sys/class/thermal/thermal_zone0/temp)
	cpu_temp1=$(($cpu_temp/1000))
	cpu_temp_up=$(($cpu_temp1/100))
	cpuTempM=$(($cpu_temp_up % $cpu_temp))
	cpuFreq=`cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq | sed 's/.\{$
	echo CPU temp"="$cpu_temp1"."$cpuTempM"'C"
	echo GPU $(/opt/vc/bin/vcgencmd measure_temp)
	echo CPU Clock Rate"="$cpuFreq
	

Press ctrl+x and then press y to save and exit file. Run it using sh CPUstat.sh. It will tell your the temperature. It is important because if you are runnig your Raspberry Pi for too long, it is likely to heat up. I am sure you don’t wanna brick your pi. So it will let you keep a check on temperature. If it’s above 70C, then you might wanna add a heat sink to it. Mind it, the pi was built to sit inside a mobile device as well with no airflow. So it can bear high temperatures. But I would still recommend you to use a heat sink if the temperature is above 70C.

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