The State Institute for Drug Control (ŠÚKL) warns that high temperatures can degrade medicines through invisible chemical degradation of active substances or changes in the physical form of the drug, which threatens the safety and efficacy of treatment. Most medicines should be stored in a dry and dark place at temperatures up to 25 °C, although some medicines such as insulin require refrigeration. ŠÚKL particularly warns against ordering medicines to exterior self-service boxes, which become greenhouses in summer with temperatures reaching 40 to 50 °C, far exceeding storage limits. Patients should never leave medicines in direct sunlight, store them away from bathrooms and kitchens, and regularly check expiration dates. When using certain medicines, the skin is sensitive to sunlight and UV radiation, which can cause rashes, redness, swelling, or burns, so it is recommended to limit sun exposure and use sun protection.