Cryokinesis is a fancy-shmancy way of saying, "I can make things cold". It is an application of thermokinesis and is found in many different elements of speculative fiction. Cryokinesis involves the science of cryonics, but has the added benefit in allowing an individual the ability to not only lower the ambient temperature to varying degrees, but they can also generate, manipulate and sometimes even project ice. There are also many weapons, body armors and other types of equipment that can perform similar functions including cold rays, freeze guns, ice cannons, etc.
In Marvel Comics, the most well-known character to possess this power is Bobby Drake, aka Iceman. Iceman is often seen demonstrating this ability by coating his entire body in a sheathe of ice and generating sustained constructs of varying shapes made out of ice, including ice sleds, bridges, stripper poles, etc. Other Marvel Comics characters who can manipulate temperatures in such a fashion include The Blizzard, Jack Frost, Water Witch, Snowbird and the Asgardian ice giant, Ymir. The Iron Man foe, the Mandarin possesses a ring that can generate a cold ray. Iceman's partner on the X-Men, Ororo Munroe, aka Storm, can control all elements of weather, including temperature.
In DC Comics, there are many characters who possess some form of ice generation. One of the more notable examples is Mister Freeze, who is a classic Batman villain. There is also Captain Cold, a foe of the Flash, who uses a Cold Gun and is most often seen wearing a nifty blue and white parka. Characters with similar abilities include Icemaiden, Chillblaine and Killer Frost.