Device for monitoring the temperature including: at least a thermally insulated and watertight case, including at least a CPU board, having a processor and a memory containing a data sampling, processing, storage, routing and transmission software to be run by said processor, at least a battery, a wireless multihop communication systems and a global positioning detection system with at least one antenna, said wireless multihop communication systems and said global positioning detection system being configured to be kept in a minimum power consumption state when inactive, the case being designed as a floating system wherein the case is adapted to float in a predetermined position; at least one stand, projecting from the case, said at least one stand supporting one or more external sesors including one or more temperature sensors, said at least one stand being configured to be submerged when the case floats, said CPU board being configured to sample data from said one or more temperature sensors; and a charging system, for charging said at least battery, said charging system including a photovoltaic panel, said device being characterised in that said thermally insulated and watertight case further comprises a low-power sensor array, connected to said CPU board, including at least an internal temperature sensor, a water presence sensor and a ground contact sensor; and in that said software causes said processor to: detect and manage a data stream from said low-power sensor array, said data stream being related with anomaly conditions and related reactive actions, emit a signal to awake said wireless multihop communication system and said global positioning detection system from said minimum power consumption state, when said internal temperature and said ground contact sensor detect water contact and a floating condition, after emitting said signal to awake said wireless multihop communication system and said global positioning detection system, allow the wireless multihop communication systems to transmit the positioning data and sampled data which are locally stored and have yet to be transmitted. at least a thermally insulated and watertight case, including at least a CPU board, having a processor and a memory containing a data sampling, processing, storage, routing and transmission software to be run by said processor, at least a battery, a wireless multihop communication systems and a global positioning detection system with at least one antenna, said wireless multihop communication systems and said global positioning detection system being configured to be kept in a minimum power consumption state when inactive, the case being designed as a floating system wherein the case is adapted to float in a predetermined position; at least one stand, projecting from the case, said at least one stand supporting one or more external sesors including one or more temperature sensors, said at least one stand being configured to be submerged when the case floats, said CPU board being configured to sample data from said one or more temperature sensors; and a charging system, for charging said at least battery, said charging system including a photovoltaic panel, said device being characterised in that said thermally insulated and watertight case further comprises a low-power sensor array, connected to said CPU board, including at least an internal temperature sensor, a water presence sensor and a ground contact sensor; and in that said software causes said processor to: detect and manage a data stream from said low-power sensor array, said data stream being related with anomaly conditions and related reactive actions, emit a signal to awake said wireless multihop communication system and said global positioning detection system from said minimum power consumption state, when said internal temperature and said ground contact sensor detect water contact and a floating condition, after emitting said signal to awake said wireless multihop communication system and said global positioning detection system, allow the wireless multihop communication systems to transmit the positioning data and sampled data which are locally stored and have yet to be transmitted. detect and manage a data stream from said low-power sensor array, said data stream being related with anomaly conditions and related reactive actions, emit a signal to awake said wireless multihop communication system and said global positioning detection system from said minimum power consumption state, when said internal temperature and said ground contact sensor detect water contact and a floating condition, after emitting said signal to awake said wireless multihop communication system and said global positioning detection system, allow the wireless multihop communication systems to transmit the positioning data and sampled data which are locally stored and have yet to be transmitted.