Well, if you've managed to snag a place to stay at the HVNP, make the effort to take a drive to see the lava path at night. Follow road to the bottom of Chain of Craters road and if lava is visible, you will see the glowing reds along the mountain.
Dress Code: Light windbreaker is nice to have ... it can get breezy as well as have sudden unexpected rain showers. Wear comfortable walking shoes, and carry a good flashlight.
Nothing else, just 2 main reasons;
1st is for safty reason as we can clearly seen the active lava flow at night.