As the smoke eases, firefighters then move into the forest on foot to try and contain the latest flare-up. They are the principal concern for the thousands of crews and volunteers combating the wildfires that have raged here for a week, forcing tens of thousands of residents and tourists to flee. As temperatures peak at around 40C, fires restarting on their own are a constant threat. It simply descends as you travel west from Bordeaux along empty roads and through deserted villages. It explains how the wildfires have spread at the rate they have.