# Sapient aquatic species substituting geothermal vents for fire

In a question I saw on here a while back, somebody said that the development of a sapient, technologically progressing species requires fire, and thus such a phenomenon could not occur under water.

However, geothermal vents can become quite hot, and so could it be possible for an underwater species to use that for purposes that would normally require a fire, such as cooking meat and melting metal and such?

If such conditions are not possible on earth, could a situation allow this on other planets? And what would be the effects of the required changes?

Thank you!