The touch from the light mage had shared a little mana with Walker. But that mana had the small amount of life mana that the life mage could control within himself. It was very easy to see that the tiniest bit of life mana carried a decent amount of strength. However, that was just it, life mana was hard to gather in general. But the same could be said about death mana since Walker had attempted to grasp some understanding over that as well.
The heat that he could feel now though was his own life mana. Every being had life mana in them. That was what the life mage had said and that made a lot of sense. Everything was alive at some point in time.