The hot desert where they filmed was actually about ten degrees Celsius (fifty degrees Fahrenheit). They were misting water on the actors to make it appear as if they were sweating.
Pitch Black was supposed to be a stand-alone film, but during production, Vin Diesel and the cast and crew had become intrigued by the Riddick character and the ending, in which Riddick was supposed to die. This was changed to leave an opening for a sequel with Vin Diesel returning. The film spawned three sequels, Las Crónicas de Riddick: Dark Fury (2004) (animated), Las crónicas de Riddick (2004), and Riddick (2013).
The contacts that Vin Diesel wore to play Riddick were a prototype. After the first day of filming, when they tried to remove the contact lenses, they couldn't. Due to where they were filming, they had to have an optometrist flown in from the nearest town, three hours away. Diesel called the contacts hubcaps.
(at around 14 mins) Vin Diesel actually performed the shoulder-dislocation stunt (when Riddick breaks free for the second time) for the crew, holding a chain between his hands, although he couldn't do it with the cuffs on. The version we see is mostly him with some special effects thrown in.
The full-size spaceship stage used in the movie can be found in the Australian outback mining town of Coober Pedy, in South Australia, Australia. Bought by a local businessman soon after filming was completed, it sits out in the open. Entry to the site is on Hutchison Street, opposite Winch Street. It is marked, and can be seen clearly on Google Maps. More information can be found on the web.