Question

Why fire need heat to light up as we can even light a fire in very cold climate?

Answer 1

To start a fire, heat wood up, it gets rid of water and (non flammable) CO2 at the lower temperatures. Once you have got rid of this, it starts to give off burnable gases. Once you get it hot enough (around 200 centigrade) these gases will ignite. When they ignite, you get heat given off for the first time. This is when the fire “takes hold”. The heat given off by the gases gives off more gas, which catches fire in turn giving off more heat. When the fire reaches 450 centigrade, the carbon left from the pyrolysis will catch fire and glow as it burns without smoke or flame.