When hummingbirds use more energy than they consume, they use deep hypothermia (torpor) at night to lower energy costs. Torpor is not restorative like sleep so extended use can have physiological consequences. Our field work suggests hummingbirds might be capable of controlled shallow hypothermia. This would be a novel tool for periods of low energy intake. We will use thermal imaging to track nighttime body temperature to see if hummingbirds use the more restorative shallow hypothermia.