Chevrolet Silverado 2007 Owner's Manual page 528

The coolant level should be at or above the FULL
COLD mark. If it is not, you may have a leak at
the pressure cap or in the radiator hoses,
heater hoses, radiator, water pump, or somewhere
else in the cooling system.
528
CAUTION:
{
Heater and radiator hoses, and other
engine parts, can be very hot. Do not
touch them. If you do, you can be burned.
Do not run the engine if there is a leak. If
you run the engine, it could lose all
coolant. That could cause an engine fire,
and you could be burned. Get any leak
fixed before you drive the vehicle.
Notice: Engine damage from running your
engine without coolant is not covered by your
warranty. See Overheated Engine Protection
Operating Mode (V8 Engines Only) on page 526
for information on driving to a safe place in
an emergency.