What it is: Joico Smooth Cure Thermal Styling Protectant is a styling spray which protects and smoothes the hair. What it does: This luxurious thermal protector spray is the perfect protective step to your styling regime and protects from thermal damage up to 450°F and humidity whilst preventing texture and curl reversion. Smooth Cure Thermal Styling Protectant leaves the hair frizz-free, visibly smoother and healthier looking. What else you need to know: Hydrolysed Keratin forms a durable, flexible shield of Keratin which reacts with sunlight and pollution to protect the hair from environmental damage and colour fading.