This document introduces Cielution LLC and their technologies for chip-to-system thermal co-design of electronics. It discusses the need for thermally aware design with the proliferation of 3D stacked chips and heterogeneous integration. A case study demonstrates how hot spot proximity significantly impacts temperature. Cielution's CielSpot tool generates compact thermal models from detailed simulations for fast evaluation in design. CielSpot was validated against detailed simulations and shown to provide accurate temperatures within 1% while being much faster than CFD.