Visitors to the UK using NHS
References
http://www.nhs.uk/NHSEngland/AboutNHSservices/uk-visitors/Pages/accessing-nhs-services.aspx
http://www.nhs.uk/NHSEngland/AboutNHSservices/uk-visitors/Pages/visitors-from-the-eu-eea.aspx
http://www.nhs.uk/NHSEngland/Healthcareabroad/EHIC/Pages/about-the-ehic.aspx