In our classes, we don't need to notify parents that a child has bumped their head as they are usually with them when it happens (thankfully it's very rare though ). I think a slip of paper that lists head injury symptoms would still be a good idea though as the symptoms often appear later when the child has returned home. (I'll get onto it right now!)

The problem we have is keeping ice/gel packs cool to apply to bumped heads as we don't have 'premises' as such and can't always get access to a fridge for storage. Instead we use 'instant' ice packs (you squeeze them to activate them and they then go cold very quickly). Ideal for us, but probably not necessary if you have access to a fridge. They are a bit pricey (best to buy in bulk) but we get ours from www.spservices.co.uk

They were reccomended to me by one our mums and have been a godsend