Generally, using any external and unnatural agent on the body may lead to possible side effects. Hair straightening is no exception. The different methods of hair straightening include direct heat and harsh chemicals which may prove dangerous at times. You cannot be sure of the product being used by your stylist.
While applying chemicals for the first time, you may be unsure if you are allergic to such compositions. It is often seen that stepping out in the sun with straightened hair may cause damage to hair health mainly because of the harmful UV rays. The chemicals might react adversely when they are exposed to direct sunlight. Therefore, it is extremely important to check the products that are used in the procedure.