One of the deepest symbols that heat represents in literature (right back to classical times) is that of Hell. For example, you can't get a much hotter image than the image of Dante's Inferno. This image is used much in Christian literature themes, and no less so in the novel 'Lord of the Flies' by William Golding. He also deals with the very deep themes of evil and hell and these equate with images of heat in the book. For me, the strongest image of this is in the choirboys finding their old warm heavy costumes too hot and itchy and inappropriate for the setting they find themselves in (hell dressed up as heaven.) So they devest themselves layer by layer of the veneer of Christianity,goodness and civilization - symbolized by the 'hell's hothouse' they are now in.
Yes, the heat is ever present on the island of the lost boys:
The beach between the palm terrace and the water was a thin stick, endless apparently, for to Ralph’s left the perspectives of palm and beach and water drew to a point at infinity; and always, almost visible, was the heat.
“They’re all dead,” said Piggy, “an’ this is an island. Nobody don’t know we’re here. Your dad don’t know, nobody don’t know—”
His lips quivered and the spectacles were dimmed with mist.
“We may stay here till we die.”
With that word the heat seemed to increase till it became a threatening weight and the lagoon attacked them with a blinding effulgence.
Beyond the screen of leaves the sunlight pelted down and the butterflies danced in the middle their unending dance. He [Simon] knelt down and the arrow of the sun fell on him. That other time the air had seemed to vibrate with heat; but now it threatened. Soon the sweat was running from his long coarse hair. He shifted restlessly but there was no avoiding the sun. Presently he was thirsty, and then very thirsty.
The afternoon wore on, hazy and dreadful with damp heat; the sow staggered her way ahead of them, bleeding and mad, and the hunters followed, wedded to her in lust, excited by the long chase and the dropped blood.
You cannot go five pages in the novel without encountering the heat again and again; it is a reality of the boys' world that is inescapable. It is oppressive, it is tiring, and it wears everyone down and frays nerves.
It is also a reason to undress, to shed the last reminders of one's civilized self: the more naked you are, the more basic, the more animal, the more savage.
Could the heat also suggest the fires of hell, the possibility and proximity of the boys' inbred propensity for evil? What do you think?