Highly Accelerated Life Testing (HALT) involves very high rates of thermal cycling (typically accomplished using LN2 based systems) and multi-axis hammer-table vibration. This test is coupled with very thorough product parameter monitoring to determine instantly when a failure occurs. The function of HALT is to rapidly expose a product's weakest link in terms of its design. This weak link can be fixed and the process repeated to reveal the next most likely point of failure. Repeating this cycle results in a product with greater and greater reliability. Temperature extreme testing criteria includes specifying the minimum and maximum operating temperatures plus instructions on how the device under test should be powered, loaded and monitored.