TBreak uploaded a guide that learns newbies how to monitor GPU temperature, you can read it over here.
GPU temperature monitoring is essential when you have over-clocked your GPU. Even if you have not over-clocked your GPU, its always better to keep an eye on it, as different games under different loads can cause heat-up more than expected. Of course, there are many other factors that increase the temperatures;reducing the life of components, if not causing permanent damage. However, most people don’t know how to monitor temperatures “efficiently”. So, we are presenting a guide which will inform you of some good practices and recommended softwares which will help you remain vigilant of any over-heating issues.