Farmex showed its new wireless brooder alarm for pheasant huts - or other portable/temporary buildings used for the purpose - at the Precision Farming show.
This uses a temperature sensor in each hut that links to a wireless router (transmitter). So if the heater fails and the chicks are in danger it will send an alarm up to a mile (or more if using repeaters) to a central unit that will then transmit a text to your mobile phone.
Each sensor costs from £85, the router (which will service several sensors) costs from £135, while the central unit costs £925.