Final answer:
The maximum amount of time an infant heel warming device should be applied for is 15 seconds.
Step-by-step explanation:
The maximum amount of time an infant heel warming device should be applied for is 15 seconds. This is because the purpose of using a heel warming device is to increase blood flow and make it easier to obtain a blood sample from the infant's heel. Applying the device for longer than necessary can potentially cause discomfort or even harm to the infant.