While thinking on some source of heat (a fireplace, a bonfire, the sun, etc.), chant, if you are of the fire element:
I am warm,
I am fire,
All this warmth
is my desire (x13)
If you are not of the fire element, chant:
I am warm,
Warm as fire,
All this warmth
is my desire (x13)
SOURCE: SpellsandMagic.com