Final answer:
To calculate the percentage of body surface burned, we can use the 'rule of nines' method. According to this method, specific anatomical areas are associated with a percentage that is a factor of nine. In this case, approximately 31.5% of the infant's body surface is burned.
Step-by-step explanation:
To calculate the percentage of body surface burned in this case, we can use the 'rule of nines' method. According to this method, specific anatomical areas are associated with a percentage that is a factor of nine. According to Figure 5.23, the head is associated with 9% of the body surface, the trunk (including the front and back) is associated with 36% of the body surface, and each leg is associated with 18% of the body surface. Since only half of the head is burned, we can calculate the percentage of the body surface burned as follows:
Percentage burned = (Head percentage + Trunk percentage + Leg percentage) / 2 = (9 + 36 + 18) / 2 = 63 / 2 = 31.5%.
Therefore, approximately 31.5% of the infant's body surface is burned.