The terraced home in Boundary Street, off Preston Road, caught fire at around 3.30pm, with the blaze swiftly spreading throughout the home.
A woman and her 12-year-old son were trapped upstairs fearing for their lives until two brave neighbours rushed to their rescue.
The men quickly grabbed a ladder from their work van and rescued the young boy and his mum from the upstairs window.
According to reports, the downstairs window blew out and the flames took hold just moments after their escape.
Fire crews from Leyland and Bamber Bridge arrived just minutes later as the blaze tore through the home.
The fire service said the woman and her son were treated by paramedics at the scene for smoke inhalation and burns before being taken to hospital.
Firefighters battled the blaze wearing breathing apparatus and managed to rescue the family's cat from the smoke-filled home, using a pet ventilator to give it oxygen therapy. The cat is currently in the care of a local vets.
The fire service is still investigating the cause of the fire, but it is believed to have been caused by an electrical fault.
A fire service spokesman said: "Three fire crews from Leyland and Bamber Bridge were called to a house fire on Boundary Street in Leyland.
"The property was well alight when firefighters arrived.
"Four firefighters wearing breathing apparatus used two hose reels to tackle the fire.
"They also used thermal imaging cameras and a ventilation unit to reduce smoke and check for fire spread.
"There was one casualty rescued by a neighbour before firefighters arrived.
"They needed treatment from paramedics at the scene for smoke inhalation and burns.
"Fire crews were in attendance around four hours."
Relatives of the family said the woman and her son have "lost absolutely everything" in the fire. A crowdfunding page has been set up to help the family here.
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