Unless you're moving faster than possible for your particles to return to equilibrium. (either via conduction or via radiation) After all, heat transfer is a l

Unless you're moving faster than possible for your particles to return to equilibrium. (either via conduction or via radiation) After all, heat transfer is a large scale statistical phenomenon. So, if you're moving fast, despite the low density you're hitting a lot of (anisotropic) fast moving particles. This is a difference between static friction and dynamic collisions. This is why space ships still need heat shields bigger than expected by just friction alone. Edit: yes it is related to maximum dynamic pressure, you could call it maximum heat differential.