Depends on your hair properties, what products you use, the temperature of the dryer, if you dry to bone dry or still damp and air dry the rest. Some articles you might find useful
THE NATURAL HAVEN: Straightening Facts :How hot is too hot?
THE NATURAL HAVEN: Blow Drying Reduces Moisture in Hair (even with low heat!)
THE NATURAL HAVEN: Thermal protection: Do they really work?
How To Protect Your Hair From Heat Damage
2a-2c, medium texture, porous/ colour treated. Three years CG. Past bra strap length heading for waist.

CO-wash: Inecto coconut/ Elvive Volume Collagen
Treatments: Komaza Care Matani, coconut/ sweet almond oils, Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss Ultimate Volume, various Elvive
Styler: Umberto Giannini jelly, Boots Essentials gel
Flour sack towel, pixie diffuse or air dry.
Experimenting with: benign neglect