Everything

Heat and its absence are likewise controlled by the Forces Sphere. And as Mage 20’s Environmental Hazards section attests, significant fluctuations of temperature extremes may be dangerous in their own right.

As a general rule, assume that Forces 2 allows the mage to raise or lower temperatures within a spectrum of comfort and discomfort, while Forces 3 and higher creates temperature extremes that are severe enough to cause damage. As shown in the

Extreme degrees of cold – the type of cold that freezes matter or living tissue solid – may inflict lethal or aggravated damage too, especially if someone follows up that freezing with a physical attack that shatters the frozen material. (See the film Snowpiercer for a literally chilling example.) Assume that this level of cold demands Forces 4 or 5, while the same Ranks are essential when a mage wishes to turn metal into molten slag.