Which type of flame is good for heating in Bunsen burner?

A Bunsen Burner has an air hole at the base of the burner tube.

When closed', the flame is bright yellow and slick. The flame is 'cool'. The yellow colur are white hot particles of carbon.

When 'open,' the flame is pale blue and roaring. The flame is 'hot'. The pale blue colour is carbon dioxide being formed from atmospheric oxygen.