Why did your window fog up, and what you need to do to see things clearly again?
The problem with your window most likely a broken window seal. Today’s windows have two or three panes of glass separated by air space and sealed around the edges with a flexible elastic sealant to keep humidity out, unlike single panes windows of the past. These insulated glass unit (IGU) windows are known as double-pane, multipaned, or thermopane. The gas found between the panes of glass contains an inert gas, such as argon or krypton. The gas helps reduce the transfer of outdoor heat or cold through the window.
The most common sign of a broken window seal is visible condensation.