A surface heat-exchanger body for vehicles, aircrafts or ships, with an interconnected heat pipe-channel system which is hermetically closed and arranged distributed over an area; as a result of a separate line-shaped heat source which extends along the heat-exchanger body and which may be formed by a heating channel, a heating rod or the like, heat is supplied to the heat-exchanger body which is distributed and given off by the heat pipe-channel system to the adjoining space with a slight temperature drop inside of the heat-exchanger body; for a horizontal installation of the heat-exchanger body, intersecting or star-shaped channel sections are provided inside of the heat pipe-channel system which always return the condensate to the condensate collector independently of the direction of the resultant of gravity and inertia forces; the condensate collector may be constructed in the form of a closed annular line either concentrically on the inside of the surface heat-exchanger body or along the outer edge; to enhance the condensate return, the surface heat-exchanger body may be slightly arched, whereby the condensate collector must be placed at the geodetically lowest place.