Norma is living in her apartment and painting a picture of the sun in the sky. She looks out the window where the sun beats down mercilessly, then pours herself a small glass of water from her limited supply. A young girl, Suzy knocks on her door and Norma offers her a glass of water. Suzy's parents are packed and ready to leave and call Suzy away. They explain to Norma and her landlady, Mrs. Bronson, that they're heading north to avoid the heat, despite the gas shortages and traffic jams. They say goodbye and leave, and Mrs. Bronson wonders if Norma will leave too. Norma says that she isn't going and wonders if the whole thing is a dream. She hopes to wake up in a cool bed and shadows on the street. Mrs. Bronson notes that it's been a month since the Earth slipped out of orbit and started falling toward the Sun: and despite the daylight the time is five minutes to midnight.
Later, Norma returns home from the grocery store, having stolen supplies from the unattended place. She has brought several cans of grapefruit juice and offers Mrs. Bronson a glance. Mrs. Bronson starts to lose it and then apologizes for acting like an animal. The announcer goes on the air to inform listeners that the temperature is up to 110 degrees and will be worse the next day. He tells people to lock their doors and arm themselves, and then starts to crack up on the air. He's taken off the air and Norma says that he's scared too just like Mrs. Bronson. The two women share a drink… and the power goes out. Mrs. Bronson wonders what happens if it never comes on again, then looks at Norma's paintings of the sun. She asks Norma to paint something cool and refreshing, then throws a painting to the floor and hysterically pounds on it.
Norma is trying to escape the heat in her apartment and goes over to see Mrs. Bronson. they hear someone breaking in through the roof entrance and take refuge in Norma's apartment. A man calls for them to come out and Norma takes out a revolver and threatens to shoot him. He walks away but Norma doesn't see him go out the front window. Mrs. Bronson unlocks the door and the intruder storms in, taking Norma's gun away. He takes her water and then sees her paintings. He says that his wife was a painter, and that she and their baby died from the heat. He apologizes, sobbing, and begs their forgiveness, then walks away. Mrs. Bronson sees a painting that Norma has done of a waterfall. She starts to ramble about water and then stares up at the sun and collapses, dead. Norma holds her body as the paint on the canvasses starts to melt and the mercury rises high enough to shatter the thermometer. Norma screams in horror…
… and wakes up to find a doctor tending to her. It's snowing outside and Mrs. Bronson is trying to seal the windows. The doctor confirms that Norma's fever has broken but he's out of medicine and will be leaving town with his family tomorrow, to go south. Mrs. Bronson explain how she heard on the radio that the Earth has fallen out of its orbit, and is slipping further away from the sun. Within a few weeks, the planet will be entirely frozen over. Norma wakes up… and describes how wonderful it was to dream of eternal sunlight and warmth.