A new version of extended irreversible thermodynamics (EIT) satisfying a Hamiltonian structure is proposed. For pedagogical purpose, the simple problem of linear heat conduction in a rigid body is investigated to illustrate the general framework. In contrast with earlier versions of EIT wherein the heat flux was upgraded to the status of state variables, we select here its conjugate dual and higher order fluxes as new independent variables. Their time-evolution equations are formed of reversible and irreversible terms but they cannot take any arbitrary form. Restrictions are placed on the reversible terms by imposing a Hamiltonian structure while the irreversible contribution is subject to the requirement to satisfy the second law of thermodynamics. Explicit expressions of the temperature and heat flux waves are also derived.