My Inspiron which is only a year old is facing this problem

whenever I switch it on, the laptop shuts itself down sometimes after a few minutes and sometimes after 15 mins, on its own.

There is no warning and the system justs shuts down. Even if I start the system in safe mode there is no difference.

Is there an overheating problem?? or some problem with the fan of the notebook?

I cannot hear the noise of the fan right now but I am not sure whether I used to hear that noise before...Has anyone faced a same problem and if yes then what was the solution?? does it require cleaning up?