In accordance with embodiments of the present invention, a semiconductor device and method for forming a semiconductor device is described. The semiconductor device includes a substrate, including a buried dielectric layer between a base substrate and semiconductor layer. A fin is formed in the semiconductor substrate and having source and drain regions formed adjacent to each side of a gate structure. A heat conducting dielectric encapsulating a lower portion of the fin and source and drain regions above the buried dielectric layer to transfer heat away from the gate structure.