Ned Racine (William Hurt) meets the sensual Matty Walker (Kathleen Turner) during the summer of an unbearable heat wave in Florida. Their instant chemistry leads to sexual exploration in sweaty ecstay. They cool off with ice cubes and kisses only to get ready for more. Yet Matty is married. Her husband Edmund (Richard Crenna) is negligent of his adventurous wife and unsuspecting of her murderous plot. She convinces Ned to help her kill her husband so she can get his wealth and they can be together. Ned is a lawyer and used to dealing with duplicitous people. He doesn't suspect Matty could be using him, at first. Matty is used to getting what she wants and is impatient with Ned to help her out. Their trust in each other is tested as the heat of the summer wears on.