Diagnosis
Excessive external heat indicates degraded door insulation. The door has a fiberglass blanket between the inner glass and outer panel. It can settle or degrade.
How to Fix It
During pyrolytic cleaning, the outer door *will* be warm, but not dangerously hot. If it's too hot to touch, the door seal (gasket) is likely failed, letting heat past. Inspect the black rope-like gasket around the oven cavity door frame for gaps, tears, or hardness.
If That Didn't Work
The door's internal insulation may be compromised. This requires complete door disassembly to replace the insulation blanket. This is a complex repair.
Heads Up
A door that gets excessively hot during normal baking (not cleaning) is a critical safety hazard. Discontinue use and unplug the range until repaired.