It looks very serious, but it's quite light for it's size and with new and improved helmet standards, a hit to the helmet wouldn't even influence Hamilton's race. Suits are designed and tested on impact of small sharp objects like carbon fiber.
The things that are dangerous are small heavy objects, like Barichello's spring, for which they improved the helmets or big and heavy (like nosecones and wheels), where the HALO comes into play.
Let's not get carried away in stuff that looks scary, but is pretty safe.