Breathing in good air makes you more productive, healthier, and happier. Headaches, dizziness, and chronic fatigue are often caused by a high concentration of CO2 in indoor spaces. CO2 is released by humans during breathing. The higher the CO2 concentration in a room, the greater the proportion of exhaled air that is re-inhaled, which can potentially be contaminated with viruses and bacteria. Infections that spread through aerosols and droplets can be contained by improving ventilation, thereby reducing the number of new infections. The use of CO2 monitors encourages adequate ventilation and regulates excessive airing. Especially during the winter months, this can help prevent excessively low temperatures in classrooms. The gadget comes pre-calibrated and needs to be powered via a USB interface. The measured indoor air quality is indicated by an LED (green, yellow, red). Place the gadget at eye level whenever possible and not directly next to windows or immediately beside people. We recommend ventilating the room as soon as the display turns red. Ventilate the space until the indicator returns to green. With Sensirion's "MyAmbience CO2 App," you can download live values and stored data from the CO2 gadget and view them on your smartphone.