do not wash your hair with hot water. try to wash and rinse with warm water. Also make sure that your last rinse is 3 minutes of cold water rinse.
after the 3 minute cold rinse, rinse your hair vith vinegar. mix 1/8 cup of vinegar with 2 cups of lukewarm water (prepare this beforehand). rinse your hair. and then rinse with plain cold water for 1 minute or so.