95% of the time, a hedgehog out in the day is not okay. Hedgehogs are nocturnal, so being out in daylight means something is not right.
If you have found a sick or injured hedgehog in need of help, please follow the tips on my post. The post has links to hedgehog rescues around the country.
You can also call the British Hedgehog Preservation Society on 01584 890 801 They keep a list of local hedgehog rescue contacts for around the UK.