Sci-fi lovers, please come in ~

This was the beginning of a novel that was being conceived, and the setting was the near future. It started with the death of a very influential politician. The politician was found dead in his own home with a corpse of a lovedoll in his arms. In the setting, the politician had seen the ugliness and fickleness of people all his life and could not feel the warmth of the world. Therefore, he bought a lovedoll, only to get a hug after returning home from exhaustion. There were no visible wounds on the surface of the dead (but there must be some subtle traces related to the cause of death). The victim was dressed neatly and had a peaceful expression. He must have died suddenly when he was hugging Lovedoll. Then, excluding drowning, clicking, poisoning, suffocation, and any other internal diseases (note that it was internal), how did this person die? Since it was a science fiction novel, it was best to think of the cause of death from physics, chemistry, biology, or other science. Take note, it was already considered murder. Please be bold, thank you very much. The idea of a silver lining was very good, but it could not withstand scrutiny. Gas would not cause the temperature to drop unless it reacted with blood. Moreover, if the doll's skin could emit toxic substances, it would poison the rescuers. Taking a step back, if the blood suddenly froze or coagulated, the capillaries would bulge or even rupture, and the entire corpse would be very scary. It did not meet the conditions. The so-called discipline restrictions were not just a formality. I want everyone to come up with a reasonable idea from a professional point of view. At the very least, it was enough to justify himself. Attention, murder, no external injuries, reasonable. Liu 'er had once thought that short-range microwave directional launch could instantly destroy the nervous system. Who could say if it was feasible? Little Biao Jun's idea was good, but what kind of allergy could cause a person to die without pain? It would be great if there was a name or type of allergy.