Explain. You mean you can't get cold? Or you're always at a constant temp? If so, you need to provide the range of temperatures.Sterben can willingly raise his body temperature due to this, but when he is in cold situations or others are, his own mind will trigger this effect.
This is fine, just know it won't do any damage.Sterben is able to conjure small flames that require little to no mana at all this usually is the size of a candle flame or a small softball.
1.) This is a sensing, and I will add the "Spirit" element as such.Can sense small sources of heat, such as small rodents, dogs, cats, and children.
2.) You need a range for this. For an F-Class, 10m is fine. You can upgrade it as you rank up.
And your spell is fine, though it looks more like a barrier than a fireball, which is fine... I think.