Fire's intense heat is more threatening than flames and burns. Fire heat can kill. Crawling in a room on fire, the temperature at floor level can be in excess of 100 degrees Fahrenheit. If you stand up, the temperature raises to 600 degrees or more at eye level. Inhale the air at that temperature and the simple act of breathing will scorch your lungs as the clothes you are wearing melt to your skin.
Fire produces pitch black smoke.
A flame may look bright as it starts burning, but this deadly element of nature rapidly produces a thick, black smoke that can leave its survivors in complete darkness. If you wake up to a fire, the dense smoke will likely leave you disoriented and likely you will have difficulty finding your way through your home. Stay low to the floor where the most oxygen and the clearest air can be found. More people caught in fires are killed by smoke and toxic gases than from flames. Fire devours oxygen with a ravenous appetite, all the while producing toxic smoke and poisonous gases that can kill you.