The plea of temporary insanity is usually entered in order to relieve a person of criminal responsibilities due to mental conditions beyond the person's control. In other words, under certain circumstances, a person on trial may plead not guilty for doing the crime because he is not in his right mind during the offense.
It is alleged that at the time of the crime, the accused is under a great mental stress or emotional breakdown that he was unable to distinguish the difference between right and wrong and shortly after, he regained his sanity and able to function as a normal person. This type of plea is often claimed in homicide or murder cases. One example is if a man who was diagnosed with a mental illness but is undergoing a treatment and can be considered sane has a chance of claiming temporary insanity because he already has a history for the illness. This can qualify as a cognitive insanity wherein a person may have been so impaired by his mental disability that he was not able to control his actions. Another instance is when a husband caught his wife in bed with another man; he can claim that he is under a great emotional stress that he was unable to prevent his self from killing the other man. This is called irresistible impulse or volitional insanity wherein a person can distinguish the difference between right and wrong but was in so much rage that he was unable to exert self-control. Very few states allow irresistible impulse as an insanity defense.