West Sussex Fire and Rescue Service said it was alerted just before 9am to a fire at a property in Derek Road, Lancing.
"Three fire engines from Worthing and Shoreham are currently at the scene, as well an aerial ladder platform from Worthing,” a fire service spokesperson said.
“Upon arrival firefighters wearing breathing apparatus entered the property and extinguished the kitchen fire using hose reels, thermal imaging cameras and jets.
"Firefighters administered oxygen therapy to one dog and two casualties have been left in the care of crews from South East Coast Ambulance Service.
"We would urge people to avoid the area."
South East Coast Ambulance Service said both people were ‘assessed at the scene’ and then ‘transported to Worthing Hospital’.

1. Lancing house fire
Two people, and a dog, have been left in the care of paramedics after a fire at a house in Lancing. Photo: Eddie Mitchell

2. Lancing house fire
Two people, and a dog, have been left in the care of paramedics after a fire at a house in Lancing. Photo: Eddie Mitchell

3. Lancing house fire
Two people, and a dog, have been left in the care of paramedics after a fire at a house in Lancing. Photo: Eddie Mitchell

4. Lancing house fire
Two people, and a dog, have been left in the care of paramedics after a fire at a house in Lancing. Photo: Eddie Mitchell