windows - Setting environment variables in cmd has no effect

I'm trying to set up paths to VS tools to run them in command line, as per https://msdn.microsoft.com/en-us/library/x4d2c09s.aspx

I run vcvarsall x64 from elevated command prompt and check the contents of the INCLUDE variable:

Then I close command prompt, open it again and check the INCLUDE variable:

As you can see, the changes were lost when I closed CMD. How do I ensure that they make it to the system environment?

I'm using Win 8.1 if it matters.