They’re probably not hot pixels. Hot pixels are tied to sensor locations, so they would also tend to appear in dark long exposures regardless of the scene. Since you saw no issue in your near-black 150s shots, and these spots stay aligned with scene features, the cause is more likely external to the sensor.

From the answers, two likely explanations are:

• real scene lights, such as aircraft warning lights on radio towers or building-mounted beacons
• lens ghosting/internal reflections from bright lights in the frame, especially since the red dots appear to mirror bright highlights elsewhere

A good test is to compare the suspicious marks with bright lights on the opposite side of the frame; ghosting often appears flipped/inverted relative to strong light sources. If the spots move when you recompose, they are not hot pixels.

To reduce this in future:

• shield the lens from stray light
• clean the front element
• avoid very bright light sources just inside or near the frame
• try a different angle or focal length
• use a lens hood

If it were sensor-related, dark frames would reveal it clearly; your description points more toward scene lights or lens reflections.