A radial tire (10) for a heavy vehicle of construction plant type, and more particularly, the sidewalls thereof (20), arranged to minimize the temperature of the tire while guaranteeing its electrical conductivity. The tread (30) comprises two tread wings (31) and a central portion (32). The bead layer (71), the elastomeric coating compound of the carcass layer (50), the second sidewall layer (22) and the tread wing (31) constitute a preferential conductive pathway of the electric charges between the rim and the ground when the tire is mounted on its rim and flattened on the ground.