Patient data, particularly emergency data, must be available to medical personnel within a short time frame and independent of potential interruption of (mobile) network connections. Additionally, medical data is confidential information that must not openly be available to anyone with physical access to the storage media. The planned German electronic Health Card (eHC) is supposed to hold emergency data. However, the eHC smart card will not always be available to caregivers in emergency situations, e.g., unconscious patient, since it cannot be duplicated, customized or read without physical contact. We therefore propose the SemTag prototype which utilizes Near Field Communication (NFC) technology to provide secure and quick access to medical information. Caregivers have the opportunity to store encrypted medical data on tags for a particular group of addressees, e.g., for emergency cases in homecare environments. The tags can be placed on highly visible locations, e.g., entrance areas of homes and carried by the user inform of a token. Neither ubiquitous network access nor the unique eHC is necessary, to view emergency medical data within home care environments. Hence NFC tags can be regarded as a tool for information and identification alternative to distributed information systems for the collaboration of caregivers. This manuscript shows the technical storage and encryption process of emergency data on NFC tags. The technical feasibility, benefits, limitations and future research prospects of the prototype system are discussed.