A cylindrically curved panel in a state of plane strain subject to a radial temperature gradient is investigated. The ends of this thick-walled shell are presupposed to be guided in such a way that a displacement in circumferential direction may occur and that the radius of the initial middle surface remains unchanged. Then, couples act on those ends, giving rise to pure bending conditions. For a material obeying Tresca's yield criterion and the flow rule associated with it, elastic-plastic states occurring for a heated inner and/or outer surface are studied in detail. Moreover, the residual stresses after cooling are discussed.