[Sin City Stan]

I think we're talking about two kinds of heat. The ambient Temp. in the air box is probably very close to the outdoor air Temp. except when idling. However, if the metal is 250F the Infra-Red heat radiating from the metal could indeed affect the air temp sensor.

Think of a cool Fall day with bright sunshine. You're cool when in the shade and out of the sun's IR short wave radiation heat. Step into the sun and you feel the Sun's IR radiation even though the surrounding air is cool. A campfire is another good example of IR radiation.

Bottom line, get the air temp sensor outta there.