That is the warning light that means that continued driving with the engine in its current condition will destroy the motor.

I've seen it twice on my Saab: once when I blew a main coolant return line, and once when I had a major oil leak that made the oil pour straight through the engine and out.

Do not drive your vehicle until you have determined the source of the problem, unless you want to buy a new engine.

If you'd like help diagnosing the actual cause of the light, feel free to contact me.

-R