New Delhi: In a major building fire, what kills first is often not the flames but the air people breathe. Doctors say that in enclosed-space fires, people are more likely to die from suffocation, toxic smoke inhalation and oxygen deprivation than from burn injuries. The danger is compounded by poisonous gases released from burning materials, heat-related injury to the lungs and the body’s inability to get adequate oxygen.
Asphyxiation: The Primary Cause of Death
“When a person is trapped in a building that is under fire, most people die due to asphyxiation or suffocation,” said Dr Sandeep Budhiraja, group medical director at Max Healthcare who led the management of Wednesday’s incident. “As temperatures rise, oxygen levels in the air fall. At the same time, smoke contains toxic gases such as carbon monoxide and hydrogen cyanide. The smoke itself is extremely hot and can directly injure the lungs. Together, these factors can rapidly render a person unconscious.”
According to Dr Budhiraja, oxygen levels in normal air are around 21%, but in a fire-hit enclosed space they can drop sharply. “The moment oxygen levels fall significantly, a person becomes disoriented and may lose consciousness. If rescue is delayed, severe lung injury follows and survival becomes difficult,” he said.
Real-Life Impact: Malviya Nagar Fire
The dangers of smoke exposure were visible during the Malviya Nagar fire that killed 21 by Wednesday noon. At least 10 police personnel and two fire personnels were taken to AIIMS Trauma Centre after suffering smoke inhalation, choking and breathing difficulties. Some also sustained injuries after falls during the rescue operation.
Burn Injuries and Complications
Severe burns can also trigger a separate cascade of life-threatening complications. “Anything above 90% burns can be fatal. Extensive burns lead to massive fluid loss, low blood pressure, shock and later infections,” said Dr Kabir Sardana, head of dermatology at RML Hospital. “Once the skin barrier is destroyed, the risk of infection rises sharply. In many cases, patients eventually succumb to organ failure. Those with diabetes, heart disease or other underlying illnesses face even greater risks.”
Toxic Chemicals from Modern Materials
Doctors say modern buildings present an additional challenge because burning plastics, synthetic furnishings and construction materials release highly toxic chemicals.
“Carbon monoxide poisoning remains one of the commonest causes of death in closed-space fires,” said Dr Kuldeep Singh, burn and reconstructive surgeon at Apollo Hospital. “Carbon monoxide binds to haemoglobin much more strongly than oxygen, preventing oxygen from reaching vital organs. A person may become unconscious within minutes. Burning materials can also release cyanide compounds and other toxic gases that further impair oxygen utilisation.”
According to Dr Singh, smoke also carries soot particles that get deposited deep inside the respiratory tract, while inhalation of extremely hot air causes thermal injury to the trachea, bronchi and lungs.
Delayed Deterioration
Dr Vishal Kumar, reconstructive and burn surgery specialist and former faculty member at GTB Hospital, said inhalation injuries often continued to worsen even after a victim has been rescued. “Hot smoke can cause swelling of the airway and windpipe, making breathing increasingly difficult. Some patients may initially appear stable but can deteriorate rapidly due to respiratory distress,” he added.
