I like the show and usually watch it when it's on but don't take the science too seriously. In one episode a man was found dead in a meat freezer and to account for the unusual pattern of "spatter" they squirted blood from a syringe into cold air and the droplets froze and bounced of the floor.
This is obviously complete bollox; blood is mostly water with a very hi specific heat capacity and would have no were near enough time in contact with cold air for it's temperature to drop from 37 C too 0 C and freeze.

PP