Relaxed hair, as you already know, is a lot weaker than natural hair. The chemicals in the relaxer break down the protein bonds in the hair strands making your hair more susceptible to breakage and damage. Everything you do to your hair should be done carefully and with caution to avoid a setback.
Yesterday night, I decided to blow dry and flat iron my hair. I am currently 2 weeks post relaxer. After a fresh relaxer, my hair tends to have that flatness that I hate! So I always use my one and only heat pass when I'm 2 weeks post just to check to see if my thickness is still there.
Blow drying my hair safely:
-Wash/light protein/deep condition/leave-in/moisturizing heat protectant
-Air dry for 2 hours
-Section hair into 4 parts
-Before blow drying each part, apply a pea size amount of moisturizing heat protector
-Blow dry section with lukewarm air
-Use wide tooth comb to detangle section while blow drying
-Don't hold dryer to close to the hair, hold a few inches away so that the heat distributes evenly
Hair should be nice, thick and have a lot of flow!