how was wiping hurt physically and psychologically by his first experience with fire

From the text:

White Fang knew nothing about fire. It drew him as the light, in the mouth of the cave had drawn him in his early puppyhood. He crawled the several steps toward the flame. He heard Grey Beaver chuckle above him, and he knew the sound was not hostile. Then his nose touched the flame, and at the same instant his little tongue went out to it.

For a moment he was paralysed. The unknown, lurking in the midst of the sticks and moss, was savagely clutching him by the nose. He scrambled backward, bursting out in an astonished explosion of ki-yi’s.

Psychologically, he was shamed.

And then shame came to him. He knew laughter and the meaning of it. It is not given us to know how some animals know laughter, and know when they are being laughed at; but it was this same way that White Fang knew it. And he felt shame that the man-animals should be laughing at him. He turned and fled away, not from the hurt of the fire, but from the laughter that sank even deeper, and hurt in the spirit of him. And he fled to Kiche, raging at the end of her stick like an animal gone mad—to Kiche, the one creature in the world who was not laughing at him.