According to Ben Rich (author of the book I am quoting) the Air conditioner fed air into the cockpit at -40 degrees. In spite of that the thing was an oven.
The XB 70 was shirt sleeve comfort at Mach 3.0. Aerodynamic heating increases at the square of the increase in speed. So Mach 4 should be good for furnace brazing in the cockpit....
41 posted on 08/04/2015 2:17:39 PM PDT by SpeakerToAnimals
(Just scream and leap.)