Healthcare and pre-hospital-care providers (EMTs or paramedics) often use the fingernail beds as a cursory indicator of distal tissue perfusion of individuals who may be dehydrated or in shock. However, this test is not considered reliable in adults. This is known as the CRT or blanch test. The fingernail bed is briefly depressed to turn the nail-bed white. When the pressure is released, the normal pink colour should be restored within a second or two. Delayed return to pink color can be an indicator of certain shock states such as hypovolemia.