Septic Shock
Septic shock is caused when a severe infection enters the blood stream and causes low blood pressure and low blood flow. Septic shock is most common in the young and the elderly, as well as people who have depressed immune systems. Symptoms of septic shock can include high or low temperature, cool limbs and extremities, agitation, lethargy (abnormal sluggishness), fast heart rate, low blood pressure, and rapid breathing. A doctor can confirm septic shock by examining the blood for signs of infection, performing an X-ray, or looking at the levels of various gases in the blood. Septic shock is a serious emergency and can be treated by providing oxygen, restoring proper blood volume and pressure, and treating the underlying cause of the problem. Septic shock is fatal to roughly half of the people who have it.
References:
http://en.wikipedia.org/wiki/Septic_shock
http://www.nlm.nih.gov/medlineplus/ency/article/000668.htm