Final answer:
A 3-year-old child weighing 45 pounds should be in a car safety seat appropriate for their weight and height. It's likely they will be using a forward-facing safety seat with a harness, adhering to the manufacturer's guidelines. Continual reassessment is key due to the rapid physical development during early childhood.
Step-by-step explanation:
A 3-year-old child who weighs 45 pounds should be placed in a car safety seat that is appropriate for their weight and height. According to the American Academy of Pediatrics, children should use a rear-facing car safety seat as long as possible, until they reach the highest weight or height allowed by their seat. As children grow, they can transition to forward-facing seats with harnesses and then to booster seats, until seat belts fit properly. Since a 3-year-old who weighs 45 pounds is well above the average weight (as typically, a 3-year-old might weigh between 30 to 35 pounds), a forward-facing seat with a harness might be more appropriate, but it is essential to follow the manufacturer's height and weight guidelines for the specific car seat
The use of a car safety seat should be consistent with the safety standards and recommendations outlined by child safety organizations and the seat manufacturer. Given that rapid physical development occurs in infancy, toddlerhood, and early childhood, it is crucial to regularly check if the child still fits within the car seat's recommended weight and height range.