The claim states that materials that conduct electricity well are proportionately better at conducting heat, which is the foundational premise of the Wiedemann-Franz law. Multiple retrieved papers explicitly utilize or verify this proportionality in metals, alloys, and nanostructures (e.g., papers 0, 1, 2, 3, 6, 9), supporting the general rule. However, several recent studies (papers 5, 7, 8) document specific violations or deviations under specialized conditions like hydrodynamic transport or complex scattering mechanisms. Because the primary physical principle remains well-supported as a general rule while notable exceptions exist, the evidence overall supports the claim with recognized physical caveats.