If you find an ill or injured hedgehog it will probably be suffering from hypothermia, even in summer.
Place it on a hot (but not boiling hot) water bottle wrapped in a towel and put in a cardboard box or recycle box lined with newspaper.
Cover the box in a blanket, put in a quiet place to warm up and phone us immediately.
You can offer it some water and meaty cat food when it has warmed up.
Please call the British Hedgehog Preservation Society on 01584 890 801 for further advice.
Hedgehogs that need help are:
Orphaned hoglets – found out of the nest in day, or when the nest has been destroyed and the mother killed or injured.
Injured hedgehogs – with open wounds, fractures, bites, burns, or trapped in some way.
Sick hedgehogs – usually found out in the day, thin, dehydrated, possibly poisoned, or with breathing problems. Hedgehogs that are unsteady on their feet (wobbling, rocking) and one with flies around them.
Autumn juveniles – young hedgehogs born late in the year, weighing under 600g from September onwards – especially if out in the day.
Some hedgehogs should be left alone – they may be nursing females foraging in daylight during the summer, or healthy hedgehogs that have aroused in winter from hibernation. Do not assume they need help unless they are underweight or obviously ill – please ring us for advice.
Ref: http://www.helpahedgehog.org/