If it's too low early morning, this possibly is not taking place, so glucose drops too low. If this is occurring, I suggest you try taking 4000 to 8000mg/day glutamine at night. This amino acid can be used by the brain in place of glucose, but being an amino it doesn't cause a sharp drop in blood glucose levels.
Sometimes, heat lightning isn't lightning at all, but a cloud reflection of lightning from a very distant storm. In other instances, it is regular lightning which has formed far off in the distance, making a flash instead of a recognizable lightning bolt.
As an electric current moves through the plasma, there is energy dissipated in the plasma in the form of heat, just as current through a solid resistor dissipates energy in the form of heat. In the case of lightning, the temperatures involved are extremely high.