Using a novel laboratory experiment I find that hunger increases monetary impatience. This effect is larger when monetary rewards are immediate, which shows that present bias is a visceral response and can help explain why the poor tend to make more shortsighted economic decisions. Given possible confounds between physical and mental resource depletion, I also manipulated cognitive fatigue. I find that cognitive fatigue also increases monetary impatience; nevertheless this effect is driven by an increase in corner solutions. I argue that this may reflect a decrease in attention and an increase in heuristic-based choices. However, more work is needed to confirm this hypothesis.