The TR-71wf temperature data logger from T&D Corporation is a two-channel recorder with an external thermistor sensor and a measuring range of -40 to 110°C. The loggers are ideal for monitoring vaccine and drug temperatures inside medication storage units. In addition to the standard features, such as battery operation and USB communication, the TR-71wf also supports communication with mobile devices. By using a wireless LAN, temperature data is automatically uploaded to the free T&D cloud WebStorage service. The service can be used with mobile devices, such as smart phones and tablets, allowing users to monitor current readings, alerts, and data downloads.