Heat

Regular 
Raises the temperature of an object. It does not necessarily produce fire, though most things will burn if heated enough. Heat will be radiated away normally. (Use this as a guideline for playable effects – don’t try to turn the spell into a physics exercise!) 
Any wizard planning to make extensive use of this spell should arm himself with a list of the melting points of various materials. The spell can have drawbacks. If you were in jail, you might melt your way through the bars . . . but the radiated heat would probably broil you first.

Duration: 1 minute. Each minute raises the target’s temperature by 20°. Maximum temperature possible with this spell is 2,800°. 
Cost: 1 for an object up to the size of a fist, 2 for an object up to one cubic yard, and 2 per cubic yard for a larger object. Temperature change can be doubled to 40° per minute for double cost, tripled to 60° per minute for triple cost, and so on. Slower heating costs no less. Same cost to maintain. 
Time to cast: 1 minute. 
Prerequisites: Create Fire and Shape Fire.

Item 
Staff, wand, or jewelry.  
Energy cost to create: 400; item must include a ruby worth $300.