A blade with an airfoil profile for a gas turbine includes at least two opposite walls enclosing the inner part of the blade which form cooling channels and method of cooling the blade with a reduced cooling fluid flow rate at a side towards the bottom part of the blade in comparison to the side at the top part, wherein the airfoil profile extends from a bottom to a top part of the blade and at least one direct cooling fluid inlet is arranged at the bottom part of the blade, where at least one set of ribs is respectively arranged on the two walls, extending from the respective wall into the inner part of the blade, forming cooling channels in-between ribs with a channel cross-section smaller at the side towards the bottom part of the blade compared to the side at the top part.