Step 1	With the test item in the chamber in its operational configuration, install any additional temperature sensors necessary to measure the maximum temperature response of the test item, ensuring the functioning components are included.
Step 2	If performing the constant temperature exposure, go to Step 3. For cycling temperature exposure, go to Step 8.
Step 3	Constant temperature exposure. Adjust the chamber air conditions to the required temperature (and humidity, if applicable) at which the materiel must operate at rate not to exceed 3 °C/min (5 °F/min).
Step 4	Maintain the chamber conditions at least two hours following test item temperature stabilization (see Part One, paragraph 5.4). If not possible to instrument internal components, base the additional soak time on thermal analysis or previously measured data to ensure temperature stabilization throughout the test item.
Step 5	Conduct as thorough a visual examination of the test item as possible considering chamber access limitations, and document the results for comparison with pretest data.
Step 6	Operate the test item and allow its temperature to re-stabilize. Conduct an operational checkout of the test item in accordance with the test plan and document the results for comparison with pretest data. If the test item fails to operate as intended, follow the guidance in paragraph 4.3.2 for test item failure.
Step 7	Skip Steps 8 through 10 and proceed directly to Step 11.
Step 8	Cycling temperature exposure. Adjust the chamber air temperature (and humidity, if applicable) to the initial conditions, of the operational cycle appropriate for materiel deployment, at a rate not to exceed 3 °C/min (5 °F/min). Maintain until the test item's temperature has stabilized.
Step 9	Expose the test item to at least three cycles or the number of cycles necessary to assure repeated test item response. Document the maximum test item response temperature. Conduct as complete a visual examination of the test item as possible considering chamber access limitations. Document the results.
Step 10	Operate the test item during the maximum test item temperature response period of the exposure cycle. If the test item fails to operate as intended, follow the guidance in paragraph 4.3.2 for test item failure. The maximum test item temperature response period may not coincide with the maximum temperature cycle conditions because of the thermal lag of the test item. Repeat until a successful operational checkout of the test item has been accomplished in accordance with the approved test plan, and the results have been documented.
Step 11	With the test item not operating, adjust the chamber air temperature to standard ambient conditions and maintain until the test item temperature has stabilized.