What is the recommended action when driving in heavy rain?

Using low-beam headlights while driving in heavy rain is the recommended action because they provide better visibility without causing glare on the waterlogged road and the rain itself. High-beam headlights can reflect off the rain, creating a blinding effect that reduces visibility for both the driver and other motorists. Low-beam headlights are designed to illuminate the road ahead more effectively in these conditions, allowing for safer navigation through reduced visibility caused by heavy rain.