What is wrong with the catalytic converter glows bright orange?

I have a 98 Chevy Z71 P/U Vortec 5.7, it hasn't been starting up, I changed the plug wires, I checked the crank sensor, I looked underneath after I manged to start it and it was glowing bright orange, the catalytic converter or I mean converters were both orange.|||Had the same experience with a Dodge van, could see bright glow under vehicle at night. Don't drive it until you get it replaced.|||its pug up unsafe to drive WILL CATCH ON FIRE,|||If the cat glows this is due to a blocked cat, you need new ones.|||it could be running lean not getting enough fuel or it is getting to much fuel. If it is lean you are super heating the converters. and if there is to much fuel the converter uses the extra fuel to get even hotter like adding fuel to the fire the fuel pressure regulator will do this if it is leaking. and lean try checking the map sensor|||burning too rich, check codes if any