Originally posted by Mindset
Show me a canon source that says that.
According to Marvel's very own website: http://www.marvel.com/universe/Iceman
Powers
Iceman is able to lower his external and internal body temperature without harm to himself, thereby radiating intense cold from his body. Iceman is able to reach -105 degrees Fahrenheit within a few seconds, and is immune to sub-zero temperatures around him.
In addition, Iceman can freeze any moisture in the air around him into unusually hard ice, and thereby form simple objects such as slides, ladders, shields, and bats. Iceman can also augment his ice form with extraneous moisture to enhance his strength and durability, and can reshape his body's ice form at will by using any available moisture from his surrounding environment. Similarly, Iceman can rebuild his ice form if any part of it is broken or if it is shattered completely without suffering any permanent damage.
Previously, Iceman was able to transform his body into solid ice and back to human form at will. For a time, however, his body was permanently transformed into solid ice as a result of a secondary mutation. After M-day, Iceman appeared to have lost his powers, returing to human form. However, this was revealed by Emma Frost as a mental block, and Iceman later regained his powers, along with the ability to change from human to ice form.
Iceman also possesses the potential to transport himself quickly over great distances through nearby flows of water by merging his body’s molecules with those of the stream.