Answer:
Implies they are less sensible or suffer less with what their hearts feel.
Step-by-step explanation:
The phrase “hardened their hearts” in this excerpt of The War of the Worlds is like a metaphor, because the heart itself cannot be hardened, it means they were stronger or were made harder with their feelings and emotions due to the pressure of necessity, “hardened their hearts” implies they are less sensible or suffer less with what their hearts feel.