Meet the RV PetSafety Pet Monitor 4G Lite: a Verizon 4G connected pet environment sensor that can track temperature and humidity and alert you via SMS or e-mail. The device is compatible with iOS/Android devices. You can configure up to 5 emails or phone numbers for safety alerts.
The device has a battery that lasts up to 2 days without battery. You can get yours for under $150 at this time.