On my block it seems that the word “helmet” is unknown to vocabulary but such as Lexus is not. I may comment to the child because the parents obviously don’t care!
My earlier comment to similar posting was about a frum pediatric neurologist who knocks on peoples door and tells them(when he notes such as riding bikes without helmets),”…then you come crying to me to save your child”. I also commented that Cabrini Hospital(i know they close but the patients were transferred elsewhere) had one floor just for children who were unfortunately just lying in bed, some as result of such as TBI included bike injuries due to not wearing protective head gear.