Abstract: A high temperature testing system for an electronic device may include a testing chamber in which the temperature of ambient air in the testing chamber may be maintained at a desired testing temperature and the surface temperature of the electronic device may be maintained at a second desired testing temperature, where the ambient air temperature and the surface temperature of the electronic device may be set to be equal to one another. In one implementation, a system may control operation of a fan based on the surface temperature of the electronic device. The system may further include a testing apparatus that includes a heat exchanger connected to an inlet hose such that blown air is passed over the heat exchanger to cool the heat exchanger. A temperature sensor may be attached to the heat exchanger and may generate the temperature signal.