Meet the Wireless Alert TP from Lascar Electronics: an app smart thermometer that combines with your iOS or Android device to show you temperatures between -40 to 125C. It notifies you via email when temperature goes past the limits you have set. The device can send daily to monthly summary reports.
Wireless Alert TP has an LED indicator that flashes to get your attention when temperature goes outside your set threshold. Its battery lasts up to 2 years.[where to get it]