radiation

The orks were a river flowing by torchlight, carrying sacks of scrap for the fires, and pulling wagons full of brand-new shells. But they were knackered. Their washed-out, soot-dark faces looked glumly up at their Prophet, and as I looked along with the clan-bosses, I realised what a state they was in.
The burns were new. Radiation’s quite nice for orks, which is lucky, given how most meks reckon that shielding reactors is boring. But there are limits. And when there was no space left to put up hammocks round the warmth of the forges, the work mobs had started sleeping in great stinking drifts next to the atomic cores of the giant new tanks. They had growths and blisters and that, but they figured it beat freezing solid.

Ghazghkull Thraka: Prophet of the WAAAGH!