The Pet Health Network explains that shivering in cats can be an indication of pain, anxiety, fear, nervousness or low body temperature. The website notes that an endocrine disorder known as Addison's disease can cause cats to shiver as well.
The Pet Health Network cautions pet owners not to assume that a shivering animal is merely cold as there are numerous possible underlying causes. VetInfo warns that the most common cause of shivering in cats is hypoglycemia, a condition in which the cat's blood sugar drops significantly below normal. The treatment for this condition is to feed the cat immediately to raise the blood sugar.