In the short story Neutron Star by Larry Niven, the main character Beowulf Shaeffer's face is sunburned somehow when his ship - built from a General Products starship hull - passes very fast and very close to a neutron star. These hulls were said to only allow visible light (and gravity) to penetrate (edit: at least that's how I remember it). I think there is something about blueshifting needed to explain the sunburn, but if so, is the light shifted after it passes through the window? How is the physics behind the sunburn described?
edit: I should clarify that I'm interested primarily in the explanation given in the story itself. If there is any further elaboration in other stories within the series, that would be also interesting.