Thanks for the help, guys. Last night - because it was cold - I went out at 2 in the morning to put 3 layers of towels over it. I've awoke this morning to see it has moved and has buried itself within the towels to keep warm. I've given it some of my cats food and water. I will drop by the vets when it opens (11am) and hopefully they can treat it and release it back into the park considering it's over the road from them.

Thanks a bunch for all of your replies - if the hedgehog could talk I'm sure he would thanks all of you!