  Thin layers can lead to unfavorable meshes in a finite element (FE) analysis.
Thin shell approximations (TSAs) avoid this issue by removing the need for a
mesh of the thin layer while approximating the physics across the layer by an
interface condition. Typically, a TSA requires the mesh of both sides of the
TSA interface to be conforming. To alleviate this requirement, we propose to
combine mortar methods and TSAs for solving the heat equation. The mortar TSA
method's formulation is derived and enables an independent discretization of
the subdomains on the two sides of the TSA depending on their accuracy
requirements. The method is verified by comparison with a reference FE solution
of a thermal model problem of a simplified superconducting accelerator magnet.
