If you add/change some environment variables (e.g. PATH) on windows, even after restarting 'VS Code' it will not be available in VS Code integrated terminals.
But if you open that terminal from windows (Command Prompt/Powershell/...) it will have those new/updated values!!
What should I do to refresh those environment variables? (without restart or log-out)
You need to run the following line in a new window of one of your terminals (Command Prompt, Powershell, ...):
code
It will open 'VS Code' once from them.
Now you can close and re-open 'VS Code' again as many time as you want using its normal shortcuts and have your environment variables.