The following link is a video shot by Bengt Ericsson a few years ago driving his Tiger from Las Vegas to the Furnace Creek Resort in the heart of Death Valley. 38 deg C / 100.4 deg F. His car seemed to cope quite well.
https://www.youtube.com/watch?v=IOGLe9w0unQ
https://www.youtube.com/watch?v=IOGLe9w0unQ