• Birniehill Terrace in Bathgate
Detectives are looking for a man aged between 25 and 30 who was spotted in the area at the time of the incident in Birniehill Terrace, Bathgate.
The terrified victims had to be rescued after the fire erupted at the front door at around 11.40pm on Monday.
Firefighters used a ladder to reach the occupants at a first-floor window and brought the two down to safety.
Officers are treating the blaze as "suspicious" and said inquiries were ongoing to determine whether the fire was started at the door, or flammable materials were put through the letterbox.
A 999 operator gave the elderly man life-saving advice as he waited for fire crews. Control staff at Lothian and Borders Fire and Rescue Service stayed on the phone with him and gave the occupants reassurance and advice until firefighters arrived.
The pair were alerted to the flames by a fitted smoke alarm inside the property.
A police spokesman said: "Lothian and Borders Police are investigating following a fire at a property in Birniehill Terrace, Bathgate, around 11.40pm on Monday.
"A 54-year-old woman and an 83-year-old man who were within the property were uninjured during the incident, which is being treated as suspicious.
"Officers are keen to speak with a male seen in the area at the time of the fire. He is described as white, between 25 and 30 years old, 5ft 10ins tall with an athletic build and dark stubble on his face. He was wearing a black duffel-style hooded coat.
"Anyone who saw this man in the area or has any information that can assist with our investigation is asked to contact police immediately."
The pensioner was given oxygen by ambulance staff and the woman escaped uninjured.
A fire service spokeswoman said: "They were given fire survival guidance by control staff until the crew arrived.
"When giving advice we always ask what's stopping you getting out, where are you in the house, what floor are you on, and we always tell you to get to the window if you can, make yourself visible and move away from fire or smoke."
The spokeswoman added: "Two people were trapped and had to be rescued by a crew who used a ladder to reach them.
"The man and woman did not need to go to hospital, but an elderly man was treated at the scene by ambulance staff."
A fire investigation team is also working to determine the cause of the blaze.
• A 65-YEAR-OLD woman was treated for smoke inhalation following a pan fire in her Edinburgh home last night.
The woman, who lives on Hawkhill Court at Restalrig Park, was treated at the scene.