A compact, ultrahigh vacuum, radiative heater based on pyrolytic boron nitride that efficiently directs nearly all of its radiation to the sample was designed and constructed. It is shown that the heater reaches temperatures of 1300 K experimentally at 60% of its maximum power. A COMSOL Multiphysics® simulation and an analytical model predict an ultimate temperature of up to 1500 K. Furthermore, the heater does not introduce any contamination to the sample. This is accomplished by a custom-made Nb radiation shield, which was manufactured by selective laser melting and holds a flag-style sample holder. Before manufacturing, the whole assembly was simulated with COMSOL Multiphysics to validate the design of the radiation shield.