Intellilog is a data logger in the format of a visiting card which can be mounted close to or directly onto a product, activated by the sender and read by a receiver using any NFC enabled smartphone. The temperatures of the monitored goods that were recorded since activation are displayed on the smartphone app thus enabling any deviation of the predetermined temperature to be monitored and backtracked. If required, the data can be stored, administered, analysed and interpreted in the cloud. Due to its size and flexibility, the Intellilog data logger is particularly suitable for high-value individual products. It is even possible to use the Intellilog data logger with labelling machine making it suitable for mass applications.