During a hot spell the grass turned brown were the tire tracks were on the lawn. This didn't matter if it was a zero turn or a push mower. All the lawns that were directly in the sun had this problem but the shade lawns were all right. Is this heat related stress or is there something else going on? Any preventions to this problem? The lawns were long and needed to be cut so not cutting is not an option. Thank you for your help and opinions.