Four crews (Aylesbury, Leighton Buzzard, Dunstable, Thame) attended.
Firefighters were called to a two storey residential property, ground floor electrical cupboard fire. The fire was out on arrival of the fire service.
All occupiers had evacuated the property, four adults believed to be suffering from smoke inhalation were provided with immediate emergency care by firefighters before being passed into the care of South Central Ambulance Service.
National Grid were requested to isolate to electrics.
Firefighters used a positive pressure ventilation fan to clear the property of smoke.