[. . . ] Users are also at risk of physical injury after long hours of working in front of a computer. Long work periods, bad posture, poor work habits, stress, inadequate working conditions, personal health and other factors greatly increase the risk of physical injury. Incorrect computer usage may lead to carpal tunnel syndrome, tendonitis, tenosynovitis or other musculoskeletal disorders. The following symptoms may appear in the hands, wrists, arms, shoulders, neck or back: • Numbness, or a burning or tingling sensation. [. . . ] For safety reasons, and to prolong the lifetime of the battery, charging will not occur at temperatures below 0° C (32° F) or above 40° C (104° F). The full performance of a new battery is achieved only after two or three complete charge and discharge cycles. The battery can be charged and discharged hundreds of times, but it will eventually wear out. When the operation time becomes noticeably shorter than normal, buy a new battery. Use only the approved batteries, and recharge your battery only with the approved chargers designated for this device. Accidental short-circuiting can occur when a metallic object such as a coin, clip or pen causes direct connection of the positive (+) and negative (-) terminals of the battery. ) This might happen, for example, when you carry a spare battery in Basic care and tips for using your computer - 13 your pocket or purse. Short-circuiting the terminals may damage the battery or the connecting object. The capacity and lifetime of the battery will be reduced if the battery is left in hot or cold places, such as in a closed car in summer or winter. Always try to keep the battery between 15° C and 25° C (59° F and 77° F). A device with a hot or cold battery may not work temporarily, even when the battery is fully charged. Do not switch the notebook on when wireless phone use is prohibited or when it may cause interference or danger. Disposal instructions Do not throw this electronic device into the trash when discarding. to minimize pollution and ensure utmost protection of the global environment , please recycle. For more information on the Waste from Electrical and Electronics Equipment (WEEE) regulations, visit www. Com/public/Sustainability ENERGY STAR Acer's ENERGY STAR qualified products save your money by reducing energy cost and protecting the environment without sacrificing features or performance. Acer is proud to offer our customers products with the ENERGY STAR mark. Products that are ENERGY STAR qualified use less energy and prevent greenhouse gas emissions by meeting strict energy efficiency guidelines set by the U. Acer is committed to offering products and services worldwide that help customers save money, conserve energy and improve the quality of our environment. The more energy we can save through higher energy efficiency, the more we reduce greenhouse gases and the risks of climate change. 18 - Warnings and regulatory information Note Information in this section may not apply to your computer. acer ENERGY STAR qualified products: • Produce less heat and reduce cooling loads , and warmer climates. [. . . ] It meets the requirements of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). For body worn operation, this device has been tested and meets the ICNIRP exposure guidelines and the European Standard, for use with dedicated accessories. Use of other accessories which contain metals may not ensure compliance with ICNIRP exposure guidelines. This equipment complies with the essential requirements of the European Union directive 1999/5/EC. [. . . ]