Bitter cold emanates from a circle around the caster, to a range of about 1 or 2 metres. The area of effect is stationary, not moving with the caster. If the range is set to 1 metre, the damage the spell inflicts is force * 2, if the range is set to 2 metres, the damage is equal to the force.
This spell only lasts for 3 rounds, and while it is being sustained, it encumbers as if it were three spells.