Crews from St Neots and Gamlingay were called to a home in Howitt’s Garden after renovation works caused an explosion.
Firefighters were called after someone inside the property used expanding foam in a wall cavity which caused an explosion due to the proximity of a gas stove.
The explosion caused severe structural damage to the dividing wall with the next door property and left one casualty with burns, and a second with a small burn on their arm.
Firefighters used a thermal imaging camera and gas detector whilst working at the property.
Station Commander Stuart Smith, from Cambridgeshire Fire and Rescue Service, said: “Please be aware of the contents of products that you use when carrying out DIY in your own homes, it is important to ensure a safe distance is kept between flammable materials and ignition sources such as stoves and other appliances at all times.”