A system for stimulating the neural activity of a nerve supplying the spleen for treating an acute medical condition, wherein the nerve is associated with a neurovascular bundle, preferably a splenic arterial nerve, the system comprising: at least one electrode (11, 12) for being in signaling contact with the nerve; and at least one controller electrically coupled to the at least one electrode, the at least one controller configured to control the operation of the least one electrode to apply an electrical signal to the nerve, wherein the electrical signal has a waveform that comprises one or more pulse trains, wherein the charge density per phase applied to the nerve by the electrical signal is between 5μC to 1300μC per cm 2 per phase, wherein the electrical signal produces an improvement in a physiological parameter indicative of treatment of the acute medical condition, wherein the improvement in the physiological parameter is any of the group consisting of: restoring the body temperature to between 36°C and 38°C, restoring the heart rate to 60-100 bpm, restoring the systemic arterial pressure to between 90/60 mmHg and 150/90mmHg, restoring the systemic venous pressure to about 5 mmHg in the right atrium and about 8 mmHg in the left atrium, restoring the pulmonary pressure to about 15 mmHg, restoring the central venous pressure to in the range of about 3 - 8 mmHg, restoring the breathing rate to 8-14 breaths per minute, an increase in oxygen saturation to ≥94%, an increase the arterial partial pressure of oxygen to 12-15 kPa, restoring the arterial partial pressure of carbon dioxide to 4.4-6.1 kPa, a reduction of pain sensation, restoring urine output to ≥0.5 ml/kg/hr, increase the level of consciousness, a reduction in the level of lactate, a change in the level of blood glucose, a change in the level of base deficit in blood and a change in the level of arterial pH, restoring lower levels of pulmonary vascular resistance while increasing systemic vascular resistance and increasing pulmonary capillary wedge pressure, reducing high levels of lipases, reducing high levels of amylases. at least one electrode (11, 12) for being in signaling contact with the nerve; and at least one controller electrically coupled to the at least one electrode, the at least one controller configured to control the operation of the least one electrode to apply an electrical signal to the nerve, wherein the electrical signal has a waveform that comprises one or more pulse trains, wherein the charge density per phase applied to the nerve by the electrical signal is between 5μC to 1300μC per cm 2 per phase, wherein the electrical signal produces an improvement in a physiological parameter indicative of treatment of the acute medical condition, wherein the improvement in the physiological parameter is any of the group consisting of: restoring the body temperature to between 36°C and 38°C, restoring the heart rate to 60-100 bpm, restoring the systemic arterial pressure to between 90/60 mmHg and 150/90mmHg, restoring the systemic venous pressure to about 5 mmHg in the right atrium and about 8 mmHg in the left atrium, restoring the pulmonary pressure to about 15 mmHg, restoring the central venous pressure to in the range of about 3 - 8 mmHg, restoring the breathing rate to 8-14 breaths per minute, an increase in oxygen saturation to ≥94%, an increase the arterial partial pressure of oxygen to 12-15 kPa, restoring the arterial partial pressure of carbon dioxide to 4.4-6.1 kPa, a reduction of pain sensation, restoring urine output to ≥0.5 ml/kg/hr, increase the level of consciousness, a reduction in the level of lactate, a change in the level of blood glucose, a change in the level of base deficit in blood and a change in the level of arterial pH, restoring lower levels of pulmonary vascular resistance while increasing systemic vascular resistance and increasing pulmonary capillary wedge pressure, reducing high levels of lipases, reducing high levels of amylases.