Astro grunted and changed places with the smaller cadet.
"Think there might be a breeze if we opened up one side of this thing?" asked Roger.
"If there was a breeze," answered Tom, "it'd be so hot, it'd be worse than what we've got inside."
"It sure is going to be a hot day," said Astro softly.
The thin fabric of the space cloth was enough to protect them from the direct rays of the sun, but offered very little protection against the heat. Soon the inside of the tent was boiling under the relentless sun.
They sat far apart, their knees pulled up, heads bowed. Once when the heat seemed unbearable, Tom opened one side of the cloth in a desperate hope that it might be a little cooler outside. A blast of hot air entered the makeshift tent and he quickly closed the opening.
About three o'clock Roger suddenly slipped backward and lay sprawled on the sand.
Tom opened one of the containers of water and dipped his shirttail into it. Astro watched him moisten Roger's lips and wipe his temples. In a few moments the cadet stirred and opened his eyes.
"I—I—don't know what happened," he said slowly. "Everything started swimming and then went black."