Thermal drones map underground embers after Cairngorms blaze

Drone crews in the Cairngorms National Park are using thermal imaging to hunt heat that burns underground long after visible flames fade. The goal is simple but critical: spot hidden hot spots before they flare back up, and direct ground teams to the exact patch of ground that needs water or soil disturbance.

In a dawn patrol that starts before sunrise, a dedicated drone pilot snakes a thermal camera over the forest. The heat glow on the screen isn’t a flame you can see with your eyes; it’s a map of residual heat trapped beneath the soil and under leaf litter. The first time the crew found eight hot spots on a single flight, a reminder that the fire can smolder underground long after the surface looks calm.

The wildfire barreled across roughly 33 square kilometers in July, scorching trees and soil. As the flames subsided, the real work began: finding pockets of warmth that could reignite. Local authorities say these underground hot spots are a real risk because they can reignite the fire if not treated. Ground teams then follow the drone’s coordinates to douse the area with water or to dig down and cool the earth.

Ground managers use these drone detections to prioritize where to send limited personnel. Ben Jones, who oversees conservation work in Abernethy, notes that with finite staff and resources, knowing the precise locations of hot spots makes the work far more efficient. Without the drones, crews would have to blanket the area and risk missing stubborn pockets that recur.

Looking ahead, researchers and park staff are adjusting the drones to perform repeat flights along the same routes. By using fixed waypoints and the same vantage points month after month, they can build a long-term picture of how the terrain recovers and where heat persists. That long view is not just about firefighting; it’s about understanding how ecosystems heal after a major fire and what conditions might trigger future blazes.

There is also interest in expanding the drone role to catch new fires earlier. Pete, the pilot in the project, says surveying from above the canopy can give responders a quick heads-up if a small hotspot starts to spread, potentially stopping a new fire before it grows.

The Cairngorms project shows how tech is increasingly part of wildfire response, not just during the blaze but in the months and years that follow. For residents of the UK, it’s a reminder that even when flames are out, the work of keeping forests safe can still be carried out by careful planning and smart use of drones.