What stage of fire is characterized by influencing the structure's environment?

The growth stage of a fire is characterized by the fire's rapid spread and the increasing intensity of heat and flames. During this stage, the fire starts to influence and change the environment around it, including the structure it is affecting. This can manifest in multiple ways, such as increased temperatures in adjacent areas, smoke production, and changes to the structural materials of the building due to heat exposure.

As the fire grows, it begins to consume more fuel, which leads to a substantial release of energy and further influences the environment. This stage is critical because it often leads to the development of conditions that can make controlling the fire significantly more difficult. The growth phase is also when structural integrity may start to be compromised, making the environment more hazardous for firefighters and necessitating strategic interventions.

Recognizing the signs of the growth stage allows responders to anticipate how the fire will behave and make informed decisions about their approach to mitigate risks and protect life and property.