After a fire, historic buildings made of stone or brick often have a chance of survival, but saving them requires swift action. The key is to quickly assess the damage and reinforce the walls to prevent collapse and further degradation. Although a building may look severely damaged, the heat from a fire often only affects the surface, leaving the deeper structure intact. This means that with proper intervention, historic buildings can be preserved rather than demolished. However, there is currently no universally accepted protocol for evaluating and repairing fire-damaged historic structures, which complicates the decision-making process. This summer, Spain faced wildfires of unprecedented scale, prompting the government to declare a national emergency for the first time. In the region of Castellón, the historic stone building known as the Nevera de Castro remains standing despite the surrounding landscape being completely devastated. Its walls are heavily blackened by smoke and heat, and a technical inspection is now required to determine its actual condition. While the visual impact of the fire is dramatic, the true extent of the damage may be less severe than it appears. Historic buildings made of masonry—stone, brick, or block—often appear entirely destroyed after a fire, but the materials used in these structures conduct heat poorly. This means that the damage is typically limited to the outer surface, with the core of the walls often remaining intact. However, wooden components such as trusses and floors are highly vulnerable to fire and can allow flames to spread between buildings. In contrast, thick masonry walls are relatively fire-resistant and can act as barriers to prevent the spread of fire. Preserving even a portion of the original structure can significantly reduce the cost of reconstruction and help maintain the historical identity of the building. To save these buildings, immediate action is essential. When a masonry wall loses its roof or wooden floors, which once provided structural support, it becomes vulnerable to collapse from wind alone. Additionally, the stone itself can begin to degrade after exposure to high heat. For example, when limestone is heated to around 750°C, the calcium carbonate in the stone decomposes into calcium oxide and carbon dioxide. If rain reaches this surface before it is protected, the calcium oxide can react with water, increasing in volume up to 20% and causing internal cracks. Without prompt protection, some types of construction may begin to disintegrate within days of a fire. Research has shown that in thick masonry walls exposed to wildfires, the heat affects only the surface, while the interior remains largely undamaged. This creates temperature differences that can cause the outer layer to crack or flake. However, the core of the wall, which is responsible for structural integrity, is often unaffected. In the case of the Monastery of San Jerónimo de Guisando, a 14th-century building in Ávila, Spain, the thick clay brick walls proved to be highly resistant to fire. Studies have shown that clay bricks, which are fired at high temperatures during manufacturing, retain their strength even when exposed to fire again. The main vulnerability in historic masonry is the mortar that binds the bricks together, which can degrade more easily than the bricks themselves. Assessing the damage to a fire-damaged building begins with observing its color. A pink or red hue indicates exposure to temperatures above 300°C, while a gray or white color suggests even higher temperatures. However, these color changes only reflect the condition of the surface. To determine the depth of the damage, engineers use methods like petrographic analysis, which involves examining thin sections of the wall under a microscope to identify microcracks. This approach was used after the 2019 fire at the Cathedral of Notre-Dame in Paris, where researchers found that the heat had not penetrated the entire thickness of the stone. The key to saving a historic building after a fire lies in acting quickly. Immediate reinforcement is necessary to support weakened structures and protect the building from further damage caused by weather. Experts emphasize the principle of minimal intervention, aiming to preserve the historical and cultural value of the structure while ensuring its safety and longevity. While some buildings may be beyond repair, others can be restored with careful and timely action. Until standardized protocols for assessing and repairing fire-damaged historic buildings are established, the decision to demolish a building should be made with caution, ensuring that the potential for preservation is fully explored.