The optimal environment is a room with a lot of natural light, at room temperature. The lower the temperature (above freezing), the longer the tulips will last. They tend to do really well in rooms with an average temperature of about 60F to 65F.
Even if the room is cool, avoid direct sunlight to the vase. The greenhouse effect will cause the inside to heat up. This can can reach uncomfortable levels, damaging the tulips and reducing their life-span.
It is also important not to over-water the bulbs. There should be at least 1/3 of the bulbs sticking out of the water. Changing the water is fine, but be careful not to damage the roots. Hold the flowers and stems carefully while pouring out the water. Refill with regular tap water