Firefighters go running into burning buildings with the sole intention of stopping the blaze and saving anyone trapped inside. But once the flames have been put out and the dust has settled, it's time to work out what caused the blaze - and that's where Dexter the East Midlands fire dog comes in.
Dexter is a three-year-old working cocker spaniel. He has been working with his handler and owner Dave Coss, 49, since July 2015 and now travels across Derbyshire, Leicestershire, Nottinghamshire and Lincolnshire to help their fire investigation teams work out the cause of fires.
Fire investigation officer Dave and Dexter work as a team. There are 15 such handlers and their dogs working for the national fire service across the country. Dave and Dexter will always work together, the teams are never switched because of the understanding between the dog and his handler.
Dexter is trained to sniff out any accelerants at the scenes of fires like petrol, which can prove that a fire was started deliberately. When Dexter finds something he is rewarded with his favourite tennis ball.
Working dogs' noses are more sensitive than current technology when it comes to detecting the causes of fires. They have helped fire investigation teams to secure a higher level of accuracy, improving the conviction rates for arson, says Dave.
He said: "He's a really hard worker and no two days with him are the same.
"I really enjoy working with Dexter and the work he does is really important to the fire service.
"It's the best job in the fire service."
Dexter never goes in unprepared to the scene of a fire. He has special boots that are used to protect his paws from glass and other sharp objects when he is carrying out his work. Some of his boots were even sent down to London in the wake of the Grenfell Tower tragedy to be used by police dogs involved in that inquiry.
Dogs are never sent to the scenes where it is still hot or while a fire is still burning, and there has so far never been an injury to a fire dog across the country, according to the London Fire Brigade.
It's not just boots Dexter has to wear though, as he also has a harness he has to wear when he needs to work at heights, a life jacket if he is working near water and even a hazardous materials suit to keep him safe from harmful chemicals.
Dave and Dexter are the only team in the East Midlands area, serving four fire services - Derbyshire, Leicestershire, Lincolnshire and Nottinghamshire.
They are called upon around 200 times a year and have investigated many high profile fires, such as a blaze in Allenton, Derby that killed the six Philpott children, which was started by their father Mick Philpott, helped by his wife Miread and a fire in Leicester that killed the Taufiq family.
The excitable dog works hard to help the team at the scene of fires, but sometimes finds himself getting into trouble with his handler, says Dave.
Dave said: "He's definitely mischevious. He's jumped out of a first floor window before when we have been on a job.
"He also ate some rat poison on another job. He was lucky I saw him do it, because we got him straight to the vet, where he was treated. Luckily, he was alright. I don't think he'll be doing that again!"
Fire dogs are selected at a young age, based on how much they like to play and the potential they have to follow orders from handlers. The pups then undergo a training programme, where they learn how to detect an ignitable substance and are rewarded each time they do.
While attending fire safety college for dogs, the pooches are tested on various disciplines, such as finding traces of a substance in a single room, in multiple rooms and in hard to find areas such as letter boxes and under stairs.
Training the dogs can cost between £6,000 and £8,000.
At the end of the work day, Dexter goes home with Dave to kick off his boots, lie back on the sofa and watch TV - much to Dave's wife's dismay.
You might think that living and working together could put a strain on Dave and Dexter's relationship, but Dave insists that they are both really happy and love working together and their partnership will carry on for many years.