I was very happy to be wearing my helmet a week ago last Sunday, when as I was riding to our church choir practice, my front wheel came loose and caused me to veer into the curb. I couldn't understand why I could not get the bike away from the curb, and I took a very hard spill, a face plant actually. Luckily, this 67 year old found a soft spot to land his face, in the bark mulch after breaking apart a small bush. I ended up with my glasses planted so hard against my face that they bit into the bridge of my nose. I also had one gouge in my cheek; at my age, it didn't hurt my looks though.
As you can see, I have a helmet which will fit over my hood, and it worked very well. the front of the helmet and the light took the main head plant force, saving my nose and teeth a more delicious bite into the bark mulch. I hit at about 12 mph, and it made a hole about six inches into the ground/bark mulch area. The outside air temperature at the time was about 32 degrees F (0 degrees C). The baseball cap I wore under the hood came down and covered my nose; there were small pieces of skin on the underside of the cap when I took it off.
I didn't make it to the choir practice, but did sing as I was able to get cleaned up in time for the church service. 'Had to drive there though. I had my camera on the bike, and tripod too thinking to take photos of the interior of the church with all the Christmas greenery still up. That's how I had it for the photos here. I left the camera at home, then found out that the Christmas greenery was taken down just after the service, so I didn't get a chance at those photos. 'Forgot to throw the camera (on a tripod) into the car when going back to church.
The helmet definitely helped in this situation, and was further forward than you see in the post-accident photos. The light was also dislodged, as it was down over the front of the helmet. I have retired that helmet, and got a new one the same day. The new one is a Snell Certified Specialized MAX XXL with a ratchet system which will allow it to fit over my hood/hat combination, or on my bare head too. The Nutcase helmet I was wearing is also a very good choice, but I only used it in winter as it would be too large for use without the hood or hat under it.