Meet the EL-Wi-Fi-TP+: a wireless temperature sensor that lets you monitor any environment and receive data over WiFi on your PC. It is accurate to +/- 0.1C. The sensor can log readings even if it loses communication to your PC or cloud. It can two channels of temperature data from -40 to +257°F. The device has a built-in rechargeable battery.
The above video provides you with more information on this device. More information is available here.