It would actually get quite cold, at 16000' you can expect the air to be well below 0 (pick your units, it's fuckin cold). The only time heating becomes an iss

It would actually get quite cold, at 16000' you can expect the air to be well below 0 (pick your units, it's fuckin cold). The only time heating becomes an issue is at supersonic velocities and is due more to compression of the atmosphere against the object then actual friction.