Ford 2008 Explorer Owner's Manual page 465

Speedometer: Indicates the current vehicle speed.
Type A
Type B
Engine coolant temperature gauge: Indicates engine coolant
temperature. At normal operating temperature, the needle will be in the
normal range (between "H" and "C"). If it enters the red section, the
engine is overheating, refer to Engine coolant in the Maintenance and
Specifications chapter. Stop the vehicle as soon as safely possible,
switch off the engine and let the engine cool.
Type A
Type B
Never remove the coolant reservoir cap while the engine is
running or hot.
2008 Explorer (exp)
Owners Guide (post-2002-fmt)
USA (fus)
Instrument Cluster
21