That trait could not be traced to any specific reasoning.
For example, though he did like fires, Allister could not be mistaken for a pyromaniac. In fact, as much as he did enjoy a healthy fire, he also found that he could spend days, weeks, and months even without it. And, even so, he would twitch not a twitch. Thus, one can assume, no pyromania.
And it was not a call to masochism. No, Allister did not need the physical to release pain or pleasure. Allister did not need an excuse to make him feel. He could cry quite easily on his own.
He cried when he was happy. He cried when he was sad. He cried when he was crying and he cried when he was laughing. He cried at weddings. He cried at funerals. He cried at his high school graduation and his university graduation. He once cried at a sequence in Gertie The Dinosaur, a Winsor McCary cartoon where a man scolds a joyful brontosaurus and causes her to cry for a fraction of a second. He felt a little of his heart break for her.
It was a trait his parents gave him. Sure, they cried together when they were sad. But, when his family was at their happiest, tears poured down their faces into puddles on their kitchen table. Their faces contorted, wrinkled, and red. And passersby could easily assume that horrible things had happened to them-an insane man with a hatchet, a pack of rabid dogs, or insane rabid dogs with hatchets, perhaps. But, they were simply loving life, laughing and crying about one of those "you just had to have been there" moments.
So no, Allister was not a masochist.
Allister liked to think that his extreme heat challenges were just one of the last visceral links he had to his earliest ancestors, Grandma and Grandpa Caveman Cromley. The heat challenges were a direct and deliberate snub to reason given to him from his monkey family of yester-millenium. They were all he had left of those hairy, poor-groomed relatives. And, in Allister’s time, it translated into a snub to pre-determined outcomes. One hundred and sixty-eight degrees kills skin cells? Well, here's a fact for you. Allister had calluses more retardant than asbestos. Bring on the frying pan handles! Go ahead. Dip them in lava. Allister was ready. And, if he was indeed crying, how could you be so quick to assume that the tears only came by way of pain?
Who’s to say that he was not just amused by it all?