How can i straighten my hair with out a blow dryer?

I have puffy, stubborn natural hair. Sometimes i use a hot comb to keep it kind of straight and manageable, but its not always straight as i want it to be. I've also been looking up bidyo of how to straighten it with a hot comb and most of them sinabi that you have to blow dry it first. So do i have to? Or can i just use the hot comb long enough so that it could fully straighten my hair.