Should probably look this up?
The answer is - Sunspots.
Sunspots are dark in appearance, but only on a visible light, and this is due to the fact that they are much cooler than the surrounding areas, but that doesn't mean by any means that the sunspots are cool, on contrary, they are very hot too. Sunspots actually are storms that appear in the lower atmosphere of the sun.
I really would think something besides the question