The Tenney WSP air-to-air thermal shock chamber is a fully automated dry shock test system capable of taking product 200°C to -70°C and back in 10 seconds or less. A moveable chamber automatically transfers the work load from one temperature chamber to the other. A dry nitrogen feed system facilitates oxygen purging in the heat chamber, preventing condensation on the metal parts of the chilled workload. A defrost heater is included to periodically defrost the cold chamber during extended tests. The lower chamber uses LN2 to reduce workload temperature.