For almost a month Europe has been living in a heat wave. Apart from the problems of health, water, fire and disruption of daily life, the aviation sector is seriously disrupted. Both on the lift of the aircraft, on the condition of the runways, on the fatigue and stress of the pilots. In the field of hot-air ballooning, the problem is still very different because balloons fly in hot air (but not above 90° in the envelope). This means carrying fewer passengers, taking off earlier and later, at times when the pilot, who has to follow the balloon’s load curve, will not have to overheat to rise into the sky. Moreover, in this period of heatwave, the winds remain quite strong which is an additional constraint. It is therefore not easy to complete the training of future pilots.