Final answer:
The child with a history of asthma complaining of chest tightness should be assessed first due to the urgent and potentially life-threatening nature of an acute asthma attack. Following this, the nurse should assess the child with a fever and cough, then the child with a fractured leg, and finally, the child with a minor laceration.
Step-by-step explanation:
The nurse must prioritize care based on the urgency and potential threat to each child's health condition. Among the given scenarios, the child who should be assessed first is a child with a history of asthma complaining of chest tightness. This symptom could indicate an acute asthma exacerbation, which can be life-threatening if not addressed promptly with interventions like bronchodilators and possible steroids. Chest tightness in asthmatics is a sign of significant respiratory distress and potential airway compromise, and thus requires immediate evaluation.
Next, the child with a fever and cough may warrant assessment, as these could be signs of an infection needing medical treatment. A child with a fractured leg in a cast is stable if there are no new symptoms, and a minor laceration on the arm, while it needs attention too, is the least urgent unless there is significant bleeding or other complications.