Commercial male broilers were used in five trials conducted to determine whether lowering the temperature during the cool portion of the 24-hr period in summer affected broiler performance. Treatments used were 24-hr linear temperature cycles ranging from a high of 35 C to a low of either 26.7 or 21.1 C. Results obtained showed that lowering the low portion of the temperature cycle from 26.7 to 21.1 C during the 24-hr period significantly increased broiler body weight at 48 days of age.