How did Iceman create ice?
The comics state his mutant ability is to emanate intense cold which can condense moisture from the air as ice formations and the mental ability to shape those ice formations into whatever structure he can imagine. However, according to the laws of thermodynamics, cold is defined as the absence of heat. Therefore, Iceman does not actually emanate cold, but rather absorbs and dispels heat. Since heat is energy, Iceman’s power then becomes a mutant ability to manipulate energy.