In spring and summer, many people shift their training outdoors. Granted, fresh air strengthens the immune system, while the sun's rays provide warmth and vitality. However, the sun's UV rays also damage the genetic material of skin cells and can cause sunburn. Damage to the genetic material also increases the risk of skin cancer. Due to climate change, skin cancer prevention will become even more important in the coming years. The right UV protection is therefore important for physical activity outdoors. This applies particularly to sports lessons as well as recreational and competitive sports or exercise therapy interventions. It is advisable to spend the midday hours in the shade, wear protective clothing, sunglasses and headgear and use sunscreen. These measures are recommended from a moderate UV index of 3 to 5. In Germany, the measures are regularly necessary from April to September. It is not entirely possible to avoid UV radiation, nor is it desirable due to the health-promoting effects of an appropriate dose. In order to reduce the risk of excessive UV radiation, sports teachers, therapists, doctors and trainers can raise awareness of UV protection and ensure there are protective conditions for training and competition for themselves and athletes. As part of the campaign "Clever in Sonne und Schatten" (Clever in Sun and Shade), the National Center for Tumor Diseases Dresden (NCT/UCC) and German Cancer Aid provide free materials for sports clubs and sports-oriented schools. Recommendations on UV protection specifically geared to cancer patients can be found in the free material entitled "Active living with cancer". The authors are also planning to develop materials for UV protection counselling as part of sports health checks in order to promote individual counselling for sports participants on UV protection and skin cancer prevention.