If the device exceeds a certain temperature threshold, it will present a temperature warning screen similar to this: An iPhone showing this message might still be able to make emergency calls. To resume use of your device as quickly as possible, turn it off, move it to a cooler environment, and allow it to cool down.
A lien on property is a type of security interest placed on a piece of property, real or personal, in order to secure a debt or obligation. While the underlying legal theories are different, in a practical sense, a lien is similar to a mortgage, in that the property that is the subject of the lien is taken and sold by the creditor to satisfy the debt of the property owner.
In the most general sense, a lien is the right to take someone elses property if an obligation is not discharged. It confers to the lien holder (creditor) an interest in the property that lasts until the property owners debt to the creditor is satisfied or otherwise released.