A 28-year-old woman is brought to the emergency department 2 hours after a house fire. She has erythematous, blistered skin over her anterior chest, abdomen, and bilateral forearms. The affected areas are painful to touch and blanch with pressure. The surrounding skin shows areas of deep red discoloration without blistering. On examination, hair on the affected areas is singed but not completely burnt off. What is the depth classification of the primary burn injury on her chest and abdomen?