All of a sudden the Park Brake light has come on in my car... Is this a warning light? There is the normal light with the ! but the P light is on on the dash. I've checked the brake fluid and it was a bit low, so i've topped that up but it's still on.... It's not flashing any kind of code. The day it came on the brakes did get quite hot driving through some hilly country with a heavy load, but no hotter than they've been before.

What does this light mean?