If you have spare time, even if only for a few months, then volunteering can be a good way of giving something to the community, enjoying yourself and passing your time in a worthwhile fashion.
If you are looking to move into a new career area, then volunteering can be an excellent way of gaining relevant experience that will confirm that this is the right direction for you. Alternatively it may show you that this direction is not right for you and save you wasting time pursuing that route. If the experience is positive, then you will gain useful evidence of your ability and also proof of your motivation and determination to succeed.
There are many volunteering opportunities available in the UK and overseas, covering activities in all areas.