Something I love is creative use of simple superpowers, so I'd thought I ask a for help coming up with the foundations of a character I've been stuck on.
Basically, their sole super power is an immunity to temperature changes.
Regardless of outside factors or exertion, this individual's body temperature remains at a uniform 70 degrees Fahrenheit (21 Celsius). This should make them clinically dead, but their biological functions are miraculously and physics-breakingly normal.
Not only is their body temperature unusual, but even the most extremes of heat and cold don't phase them. They could be laying on the north pole or sprinting through the Sahara without any changes to the amount of water they need to drink or clothes they need to wear. Burning and frost-burning are impossible, but other means of injury and death are totally viable. Smoke inhalation and starvation, for example are both still fatal.
With all that in mind, could this person become an hero, or a superhero? It doesn't have to be an all-powerful superheoic figure, like Superman; smaller tasks of heroism or good-old-plain generosity are welcome too.
In other words: how could this person use the fire-proof ability to do good? While donating 20% of his net income to charity would be kind, it doesn't concern us here for the scope of the question.
Assume that a secret identity isn't required. If anyone wants to examine how this person would fare in superhuman combat, by all means feel free.