Heating water to millions of degrees while keeping it in a liquid state is not possible under normal conditions. At such extreme temperatures, water would undergo a phase transition from a liquid to a gas, or even a plasma state, depending on the specific conditions.
As water is heated, its temperature rises until it reaches its boiling point at atmospheric pressure, which is around 100 degrees Celsius (212 degrees Fahrenheit). Beyond this temperature, the water transitions into steam (water vapor) as the intermolecular forces holding the water molecules together are overcome.
To heat water to millions of degrees, an immense amount of energy would be required. At such high temperatures, the water molecules would dissociate into hydrogen and oxygen atoms and eventually into a plasma state. Plasma is an ionized gas consisting of positively charged ions and free electrons. Observing water in this plasma state would not resemble the behavior of liquid water at all.
At extremely high temperatures and pressures, matter can exhibit exotic behavior and phase transitions, but these conditions are far beyond the capabilities of current technology. Scientists have studied matter under extreme conditions using specialized equipment and experiments, such as in high-energy physics laboratories and research on fusion reactions. However, these experiments typically involve different materials and conditions than water at everyday pressures and temperatures.
In summary, while water exhibits unique behavior near its freezing point, heating it to millions of degrees would lead to a completely different set of phenomena, such as the dissociation of water molecules into plasma. Achieving such extreme conditions for water is currently beyond our technological capabilities.