We've updated the web services tool on the platform. It is now possible to read not only the response body, but also the response headers. You are able to define a variable 'as' for all the attributes in the header when using an HTTP Request action event. Also, we've added proper handling for 'empty' JSON body responses that contain a 204 status code.
We made a video how you can assign response headers to a data model
For example, sometimes access tokens are placed in the response headers. If so, you can now read the access token from the response header and use it to authenticate the next request.