Law do protect volunteers?

I do not think there is a fear of volunteering, it is more what might happen in certain circumstances.

I volunteer with a heritage organisation and I and a fellow volunteer visited a church we care for last week and on a windy day could hear a banging in the church tower. I went up normal stairs to the first level in the tower, then a very short ladder to the next but decided not to cross a not fully boarded floor to a longer ladder and a trap door. It was unlikely to hold any perils but I held back because of concern for the HSE implications for the organisation if I did come a cropper, which I think was sensible, had a child climbed into the upper level and got stuck I wouldn't have hesitated to go further to rescue them or comfort them until help came.

Maybe the volunteering thing will mean that people won't stand by instead of helping e.g. pulling people out of the water. I seem to recall cases where the police have had to stand by and watch a disaster for fear of repercussions afterwards - 'not trained so can't do'.

The other question is rather more problematic. My last employers were very hot on health and safety but still some of the shop floor were injured - not following procedure. They were able to claim against the company and claims usually settled. However, when it came to office safety it was a different matter. No lifts to go up and down 10 flights of stairs. We used to carry all sorts up and down (trays full of cups and saucers) and I'm surprised no-one came a serious cropper. Personally I always wore flat shoes - just in case I fell. The company had all the procedures in place - make sure you hold the handrail when going up and downstairs etc.
OK so if we have a new law to protect small employers where does that leave employees who are doing what they have been told to do (verbally) but the rules say otherwise?