Should you notice any leakage on your device, proceed with caution to remove it. Work in a well-ventilated area, away from heat sources. Wear household gloves and glasses if possible. Using a toothbrush or cotton swab, remove battery leakage from the electrical contacts. Make sure the electronic device is completely dry before trying a new battery. Afterwards, wash up your hands with water and soap.
To avoid future problems, avoid mixing different battery brands in the same device. Always remove batteries from devices when you plan on not using the device for longer periods.