Pontiac 1996 Grand Prix Owner's Manual page 211

Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. Th'ey
are under pressure, and if you turn the radiator
pressure cap
--
even a little
I -
they can come out
at high speed. Never turn the cap when the
cooling system, including the radiator pressure
cap, is hot. Wait for the cooling system and
'
radiator pressure cap to cool if you ever have to
turn
the
pressure cap.