GPs are not in a position to provide individual risk assessments or letters for patients who feel that they should be exempt from wearing a face covering, and have no obligation to do so.
The government guidance on exemptions for public transport and exemptions in other circumstances where they are mandated suggests there is no requirement for people to provide evidence for exemption. Therefore, it is sufficient for an individual to self-declare this. Patients can download face covering exemption cards from a number of sources. Some examples are given below.