The moment dispatchers receive a 911 call, the clock begins ticking for responding fire agencies.
And how fast a fire engine shows up depends on many variables, such as weather conditions, traffic, trains, where responders are coming from and how clearly an address is posted.
The National Fire Protection Association's goal is for fire trucks with four personnel to arrive within four minutes, said Farmington Fire Chief Guido Smith.
And if it is a working fire, fully engulfed, at least 14 firefighters need to be at the scene within eight minutes, he said.
For the person with the emergency, those minutes can feel like an eternity.
Television shows and movies depict firefighters showing up instantly when there is an emergency, but in reality, it takes a few minutes to get into the vehicle and to get out of the station, Smith said.
And that time can be longer if the fire agency, like Farmington's, has to wait for firefighters to arrive because they have been paged.
For fire agencies like Layton, Ogden and Weber Fire District, which are staffed around the clock, the goal is to get firefighters suited up, in the trucks and on the road within a minute of the first call.
But not all Top of Utah fire stations are staffed 24/7 by full-time firefighters. Smaller agencies, like Farmington's, may have only two people staffing the station when an emergency call comes in.
And some agencies cover a lot of ground. Weber Fire District, for example, encompasses 511 square miles that includes five cities and unincorporated areas, said Weber Fire District Deputy Chief Paul Sullivan.
He said his mother "swore when my aunt was having a heart attack it took emergency personnel 20 minutes to get there in Arizona."
Sullivan checked the dispatch tapes and found it took 12 minutes.
"It's really tough to wait, and sometimes there are delays," he said.
The response time differs for each case. For example, the average response time in Tremonton, whose station is staffed completely with volunteers, is less than eight minutes, said Tremonton Fire Chief Steve Batis.
But that is if the fire is within city limits. If it's outside the city limits, the response time could be longer.
And in a rural area like Box Elder County, weather and distance are not the only factors that slow down firefighters' arrival.
Sometimes trains can delay a fire engine.
"We have to wait for trains like everyone else," Batis said.
Also, the newer, larger farm tractors sometimes block most of a road, and there is the occasional herd of cows or sheep being moved from one area to another along a street.
Ogden Fire Department is staffed with 37 firefighters spread among five stations each day, said Deputy Fire Chief Eric Bauman.
The Weber Area Consolidated Dispatch Center has helped reduce the response time between when the first call comes in and the first truck rolls out for medical and fire emergencies, he said.
In 2010, the average time to process a fire call was 1 minute, 27 seconds, Bauman said. As of January, the average time was 30 seconds.
In 2010, the average time to process a medical call was 1 minute, 44 seconds. In January, it was 44 seconds.
"That translates to a huge benefit for our citizens," Bauman said.
When the weather is bad, Layton Fire Public Information Officer Doug Bitton said, firefighters will prepare the engines so they can leave at a moment's notice.
That includes putting chains on the tires for the slick, snowy days and keeping batteries charged.
Bauman said homeowners can help by making sure their address is clearly visible, day or night, from the street.