Lancashire Fire and Rescue Service is advising people not to store combustible materials in close proximity to their homes.
This follows a fire in an outbuilding at a property in Cliffe Street, Nelson, on Saturday morning.
Fire crews were called to the incident at 6-52am and used a hose reel to prevent the fire spreading to the property.
A service spokesman said crews had spoken to the occupier and it appeared someone had been sleeping in the outbuilding from time to time but had not been seen prior to the discovery of the fire. On investigation, it came to light that the remains of bed linen were present and had contributed to the fire spread within the outbuilding.