"To treat these areas" means to take care of or address specific places or regions, usually focusing on improving or maintaining their condition or solving any issues related to them. Full definition
You can use it as a night cream every evening before bed, or spot treat the areas of your skin that are especially dry. (garnierusa.com)
Formula contains aloe to help soothe irritated skin in treated area. (hartz.com)
Nurse your baby or pump immediately after treating the area with the heat and massage; continue the massage during nursing / pumping. (motherandchildhealth.com)