Work-at-height, vented climbing helmets (Type 1, Class C) allow air to circulate to keep workers cool and have a chinstrap that keeps the helmet in place if a fall or impact occurs. Helmets enclose the back and sides of the head to protect against impact as the result of a fall. Type 1 helmets protect the head from vertical impacts caused by falling objects. Vents on Class C helmets provide a clear path for electrical arcing, so they should not be used in locations where electrical hazards are present.