Final answer:
When dealing with an infant's heart rate less than 60/min and signs of poor perfusion, during CPR, it is important to count your colleague's compressions and deliver breaths after every 30 compressions.
Step-by-step explanation:
When dealing with an infant with a heart rate less than 60/min and signs of poor perfusion, it is important to take immediate action. In this scenario, your colleague has already begun CPR, so your role would be to support their efforts. Therefore, the correct action to take would be to count your colleague's compressions out loud, and deliver 2 breaths after every 30 compressions. This ensures coordinated and effective CPR.