Creating a temporary file in PowerShell 4.0 and earlier has been possible using a number of techniques such as:
£> $file = [System.IO.Path]::GetTempFileName()
With the April 2015 WMF 5.0 preview this becomes much easier
£> $file2 = New-TemporaryFile
Mode LastWriteTime Length Name
—- ————- —— —-
-a—- 4/30/2015 12:42 PM 0 tmp1FE1.tmp
Now you can create files simply and easily without having to remember the .NET syntax.
Notice that the temporary files are automatically created in your TEMP folder.