How to monitor CPU temperature in Ubuntu 14.04

CPU temperature is usually good between 40 to 50 degrees Celsius.

To monitor CPU temperature, you can use the following:

Install lm-sensors:

sudo apt-get install lm-sensors 
sudo sensors detect
sudo service kmod start
sensors

The latest version of psensor includes the ability to show individual sensor value along with the indicator icon.
To install that:

sudo apt-add-repository ppa:jfi/ppa
sudo apt-get update
sudo apt-get install psensor

Then edit the app preferences to add this to startup.
Also, there is a setting in Sensor Preferences which show the sensor value along with the indicator icon.
Restart psensor for the settings to apply.

References:
http://askubuntu.com/questions/15832/how-do-i-get-the-cpu-temperature
https://itsfoss.com/check-laptop-cpu-temperature-ubuntu/
https://itsfoss.com/reduce-overheating-laptops-linux/