What heat does the heat protection system protect up to? 21 June 2019 10:20 It protects up to 220ºC, however we do not recommend styling hair over 185ºC. Related articles Which ghd hair styling products contain heat protection? How do I claim on my warranty? Are ghd hair products tested on animals? There is a hole in my brush, what is this for? Which hair dryer can I use the ghd professional hair dryer diffuser with?