GMC 1996 Sierra Owner's Manual page 226

Engine Overheating
(Gasoline Engine)
You will find a coolant temperature gage on your
vehicle's instrument panel. If your vehicle has a
diesel engine, see "Engine Overheating" in the Diesel
Engine Supplement.
If Steam Is Coming From Your Engine
A
CAUTION:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Just turn it off and get everyone away
from the vehicle until it cools down. Wait until
there is no sign of steam or coolant before
opening the hood.
I f you keep driving when your engine is
overheated, the liquids in it can catch
fire.
You
or
others could be badly burned. Stop your engine
if it overheats, and get out of the vehicle until the
engine is cool.
NOTICE:
If your engine catches fire because you keep
driving with no coolant, your vehicle can be
badly damaged. The costly repairs would not be
covered by your warranty.
5-10