heat shield

[rutledge01]

Is a heat shield essential for a catalytic converter

[Clanad]

The converters commonly reach temperatures of 900 degrees F., so the heat shield is essential...

[KebabMeister]

Depends on vehicle specification and how close it is to the floor pan.  But as Clanad mentions, the temperature of the Catalyst is in excess of 600 deg C so in most instances a heatshield is fitted.

[ianess]

My local exhaust centre [you can't get better....] tells me that unless you plan to drive slowly across tall dry grass then a heat-shield isn't needed.   I guess that rules out most of us but I wouldn't want to put it to the test.

[KebabMeister]

Even with a heat-shield, it is recommended you avoid any tall grass/dead leaves etc., incase of combustion.  I wouldn't like to chance it that's for sure!