I'm not a huge fan of straightening, and I'm not millitant with it either. I think I've straightened my hair a handful of times since going natural... (for my wedding is one of those times...)
Heat can be a monster, espeically when used consistently. Some people prefer to wear their natural hair straightened, and that's their business. No judgement from me, I personally think they're still natural so I wont debate the point that I've seen some natural woman fight over (whether those who straighten are "true" naturals). Not going to sit here and say they're trying to be white, rejecting their blackness, etc...I will say that using consistent heat (no matter if you use heat protectant or not) can and probably will cause permanent damage to your natural texture. So how do you safely use heat? Beats the heck out of me...I'm not here for that...As I said, I've only straightened a handful of times, so I'm not a big advocate.
I love this article (http://www.hairparlor.com/haircare-articles/hair-damage-causes.htm)
I'mma paraphrase for my girl Candra who likes to give me lip when I send her long articles to read...(Sucka).
For this post (dealing with heat)...
Straightened Hair Styles
Straightened or sedu hairstyles involve the use of some sedu hair straightener device. Normally a hair iron is used to remove the curl from the hair. Hair damage done by a sedu hair straightener device can be considerable. Anything that applies heat to the hair will have the effect of drying the strands and of making them brittle and more susceptible to breaking. Anything that causes friction or physical stress to the hair can cause hair loss. In addition, curly hair has a unique chemical structure. Sulfur atoms in hair proteins create disulfide bonds by joining together in pairs. The greater is the distance between the proteins at the time of bonding, the greater the bend in the hair when the bond is formed. Heating techniques to relax that bond literally attack the chemical structure of curly hair. Any time straightening techniques are used, the hair should be routinely moisturized. Keep split ends under control, and build times into your week when your hair can "relax" and be its natural curly self.
So if you're gonna heat straighten, be very careful...Limit it as much as possible as no amount of hot oil treatments, deep conditioners, etc., can repair the damage.