Geo Prizm 1997 Owner's Manual page 201

'
A
CAUTION:
I
Steam and scalding liquids from a hot cooling
system can blow out and burn you badly. They
are under pressure,
and
if you turn the radiator
pressure cap
--
even a little
--
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.
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