Treat your scalp with kid gloves before applying relaxer. In fact, avoid scratching, brushing, combing and even washing your scalp the week before. And don't pull your hair back in tight buns or ponytails during this time. Even the slightest amount of irritation can make your scalp sensitive and more susceptible to the nasty burn of a relaxer.
Avoid anything that will dry out your scalp one week prior to relaxing. A dry scalp will get itchy and make you want to scratch. It may be tough but this includes sweating, getting caught in the rain or using any styling products that contain alcohol. You may even want to massage a thin layer of castor oil (it tastes horrible but it's good for your hair) into your scalp every other day to ensure that your scalp is extra hydrated.
Apply a barrier cream around your entire hairline before the relaxing treatment. A barrier cream is similar to petroleum jelly, except that the consistency is a bit lighter. Use your fingertips to dab the barrier cream along your forehead, down behind your ears and then to the nape of your neck. Don't be stingy! The thicker the better.
Protect your scalp, too! This part can be a bit tricky and will require you to use a cotton swab instead of your fingers. Dab the barrier cream onto your scalp using the cotton swab. Cover your entire scalp, not missing an inch -- or the inch that you miss could be the inch that burns! Do this carefully. The key is to apply the barrier cream to the skin of your scalp, avoiding as much of your hair as possible.
Go for mild when it comes to relaxers. Whether you choose a lye or "no lye" relaxer, check the pH factor. The higher the pH factor, the higher your chances of getting burned. Relaxers have a pH between 10 and 14 -- go for the 10 if you want to reduce your chances of relaxer burn. Choosing a relaxer with a pH of 14 is just asking for trouble.
If despite your best efforts your scalp is itchy or dry, wait another week or so before you relax. Your hair and scalp will thank you.
Read the instructions carefully before applying any relaxer. Follow the timing recommendations meticulously, or you could burn more than your scalp. Relaxer is also hard on your hair and leaving it on longer than suggested by the manufacturer can result in singed hair and breakage.