Signs such as soot in airway passages or skin color changes may be useful in determining the degree of injury.
Cough: When the mucous membranes of the respiratory tract get irritated, they secrete more mucus. Bronchospasm and increased mucus lead to reflex coughing. The mucus may be either clear or black depending on the degree of burned particles deposited in the lungs and trachea.
Shortness of breath: This may be caused by direct injury to the respiratory tract leading to decreased oxygen getting to the blood. The blood itself may have decreased oxygen-carrying capacity. This could be the result of chemicals in the smoke or the inability of cells to use oxygen.
This can lead to rapid breathing resulting from the attempt to compensate for these injuries.
Hoarseness or noisy breathing: This may be a sign that fluids are collecting in the upper airway where they may cause a blockage. Also, chemicals may irritate vocal cords, causing spasm, swelling, and constriction of the upper airways.
Eyes: Eyes may become red and irritated from the smoke. The corneas may also have burns on them.