In September 1939 when war was declared, the government put a series of air raid precautions into action that they had been planning since 1935 when it had started to look as though there might be a second world war.
Members of the official Air Raid Precaution service (or ARP wardens as they were known) appeared almost overnight in every street in Britain, providing services such as advice and training on how to wear gas masks, to enforcing lots of new rules that immediately became law such as the blackout, which was designed to ensure that the German bombers wouldn't be able to see their targets in the British industrial towns. To do this, warden posts were set up on many street corners, meaning that people always knew where they could go for help.
Between the declaration of war and the first bombings on British towns in 1940 there was a long period when nothing happened. This later became known as the 'phoney war' and was a very difficult time for the air raid precaution service because a lot of people resented the way they were told to "put that light out" or had to suffer rationing and evacuation when it seemed there was no reason to. Members of the public also began to resent what they saw as the "darts brigade" because the air raid wardens had little to do in this period and some had been spotted playing darts in their air raid warden's posts to pass the time. However this soon changed when the first bombs fell and the civilians realised how important the air raid wardens were.
Air Raid Wardens had several main duties that they were trained to perform, which were all very difficult and time consuming tasks. They had to supervise the blackout, and report people to the police who continually ignored it. They had to sound the air raid sirens so that everybody knew that they had to get to the shelter, as well as supervising people getting in and out of the air raid shelters. They also had to check that everybody had their gas masks, and that they were all fitting properly, as well as sounding alerts if there was a gas attack. In addition to this, they also had to evavuate people away from unexploded bombs, and report the bombs and otehr damage to the warden control centre.