When giving chest thrusts to a choking infant, the responder should place two fingers in the center of the infant's chest, just below the nipple line. The thrusts are delivered sharply downward to a depth of about 1.5 inches (4 cm). This spot corresponds to the lower half of the breastbone (sternum). The infant should be lying face up, with their head slightly lower than the chest during the procedure.

Key Details:

• Place two fingers (index and middle) on the middle of the infant's chest just below the nipple line.
• Deliver up to five chest thrusts, pressing about 1.5 inches deep.
• The infant should be positioned face up and supported with the head lower than the chest.
• The chest thrusts aim to create pressure to help dislodge the airway obstruction.

This procedure is part of the recommended infant choking first aid sequence which also includes delivering back blows if chest thrusts do not clear the obstruction.