def METHOD_NAME(self, variables):
    T_av = variables["X-averaged cell temperature [K]"]
    T_amb = variables["Ambient temperature [K]"]
    y = pybamm.standard_spatial_vars.y
    z = pybamm.standard_spatial_vars.z
    # Subtract the edge cooling from the tab portion so as to not double count
    # Note: tab cooling is also only applied on the current collector hence
    # the (l_cn / l) and (l_cp / l) prefactors. We also still have edge cooling
    # in the region: x in (0, 1)
    h_tab_n_corrected = (self.param.n.L_cc / self.param.L) * (
        self.param.n.h_tab - self.param.h_edge(y, z)
    )
    h_tab_p_corrected = (self.param.p.L_cc / self.param.L) * (
        self.param.p.h_tab - self.param.h_edge(y, z)
    )
    negative_tab_bc = pybamm.boundary_value(
        -h_tab_n_corrected * (T_av - T_amb), "negative tab"
    )
    positive_tab_bc = pybamm.boundary_value(
        -h_tab_p_corrected * (T_av - T_amb), "positive tab"
    )
    self.boundary_conditions = {
        T_av: {
            "negative tab": (negative_tab_bc, "Neumann"),
            "positive tab": (positive_tab_bc, "Neumann"),
        }
    }