A turbine blade including a root, a vane extending in a spanwise direction, ending at a tip and including a leading edge and a trailing edge and a pressure-side wall and a suction-side wall, the vane further including at least one upstream duct configured to collect air at the root to cool the leading edge, discharging the air through holes passing through the wall of the leading edge; at least one downstream duct separate from the upstream duct and configured to collect air at the root to cool the trailing edge, discharging the air through holes passing through the pressure wall upstream from the trailing edge; an inner side cavity running along the pressure-side wall to form a heat shield insulating the downstream duct.