The question is a bit tricky! There's no "third stage eclipse" in the way you might be thinking. Here's why:

* Solar Eclipse Stages: A total solar eclipse has four main stages:

1. First Contact: The Moon begins to cover the Sun.

2. Partial Eclipse: More and more of the Sun is covered.

3. Totality: The Moon completely covers the Sun, making it dark as night.

4. Fourth Contact: The Moon begins to move away from the Sun, and the eclipse ends.

* Location Matters: You can only experience totality during a total solar eclipse if you are standing within the "path of totality". This is a narrow band on Earth's surface where the Moon's shadow falls completely.

So, to answer your question directly: Someone experiencing a total solar eclipse (which is the "third stage" of a solar eclipse) is standing within the path of totality.

Let me know if you have any other questions about eclipses!