Earth has become almost uninhabitable when 24 hours of continuous sunlight causes the thermometer to creep towards 140 degrees. In New York City, Norma and her landlady, Mrs Bronson, are the last people in their building, the rest having moved north where it is cooler. Trying to keep each other company as electricity is rationed and food and water become even more scarce, survival seems impossible. It is only a matter of time before humans can no longer exist in the unbearable heat. Then Norma wakes from her fever-induced dream to find that earth is actually freezing over. Hot or cold, is earth really doomed?