Why are very viscous liquids often heated before pumping?

Very viscous liquids are often heated before pumping because the viscosity of a liquid typically decreases as its temperature increases.12

In engineering, pumping efficiency is significantly higher for mobile liquids than for highly viscous substances like molasses. By heating a viscous fluid, its resistance to flow is reduced, which allows the pump to operate more efficiently. Additionally, maintaining appropriate flow characteristics is essential to ensure the pump receives adequate inlet pressure, as insufficient pressure can lead to cavitation—a damaging phenomenon where vapor bubbles form and collapse within the pump, causing noise, vibration, and erosion.1