vital information about the state of nhs emergency services through this, the most challenging winter they have faced. sophie hutchinson, bbc news. joining me now is our health and science correspondent nick triggle. how does this tracker work and how do people use it? it is how does this tracker work and how do people use it? do people use it? it is on the bbc website. do people use it? it is on the bbc website- it do people use it? it is on the bbc website. it was do people use it? it is on the bbc website. it was launched - do people use it? it is on the bbc website. it was launched this - website. it was launched this morning. all you have to do is put in your postcode and it will then show the weights for emergency treatment where they live. waits. there are waits for ambulances which are registered, as well. then inside accident and emergency, it tells you about what your local hospital, what the waiting time is in casual two, whether you are likely to wait over four hour