I checked the temperature of my 55 Watt SOX lamp with a non-contact thermometer.
I ran the fixture for an hour.

  Outer glass: Base/electrode area 82C - 180F  End: 72C - 162F
  Arc tube: Cathode ends 95C - 203F  U bend: 83C - 181F

I think the non-contact thermometer will read wrong behind infrared reflector deposited on the outer. The burner temperature should be at 260C, otherwise only neon-argon would glow.