Sodium metal reacting with water can produce a violent response! Sodium and water react according to the equation:

As you can see, this reaction produces heat, and it turns out that the amount of heat produced can be pretty substantial. The heat can even cause the hydrogen gas (produced in the reaction) to ignite, thus reacting according to this equation:

The heat produced by both of these reactions can even cause any currently unreacted sodium metal to also ignite and burn according to the equation:

From these reactions, it is probably clear that the reaction of sodium with water can produce quite a lot of heat!