The glowing tip of a lit cigarette, commonly referred to as the cherry, is the visible result of a continuous combustion process. This incandescent coal is where the tobacco is oxidized, generating the heat necessary to draw smoke. Understanding the cherry’s temperature provides insight into why this small ember presents a significant thermal hazard. The heat fluctuates dramatically based on air flow and the physical state of the cigarette.
Measured Temperature Ranges
The temperature within the cherry is highly dynamic, fluctuating depending on whether the cigarette is actively smoked or left to rest. When a cigarette is left untouched, the tobacco smolders slowly due to limited oxygen supply. This keeps the temperature between approximately 400°C and 700°C (752°F to 1,292°F). At this smoldering temperature, the incomplete combustion creates a visible, glowing coal that maintains enough heat to prevent the cigarette from going out.
When a person takes a puff, the temperature rises sharply due to the sudden influx of air. This rush of oxygen accelerates the combustion reaction, pushing the cherry’s internal temperature into a higher range. During active puffing, the peak temperature can reach between 800°C and 900°C (1,472°F to 1,652°F). Studies have recorded short-lived hot spots on the surface that momentarily exceed 1,000°C (1,832°F).
Variables That Influence Cherry Heat
The exact temperature reached depends on the efficiency of the combustion process, regulated by physical and environmental factors. Oxygen availability is the primary driver; increased airflow during a puff feeds the reaction, causing the temperature to spike dramatically compared to the resting state. The design of the cigarette also plays a role, particularly the paper porosity and the density of the packed tobacco.
Tightly packed tobacco or paper with low porosity restricts airflow, which tends to lower the overall burning temperature. Conversely, the moisture content within the tobacco is a factor, as overly dry material can combust too quickly and at a higher temperature. Environmental conditions, such as wind or ambient humidity, influence heat by affecting the rate of oxygen delivery and heat dissipation.
Practical Implications of High Temperature
The high temperatures sustained by the cigarette cherry, even in its cooler smoldering state, have serious real-world consequences. The resting temperature of 400°C to 700°C is well above the auto-ignition point for many common household materials. For example, ordinary paper ignites at roughly 233°C (451°F), and cotton fabric ignites around 267°C (513°F).
This temperature disparity explains why cigarettes are a leading cause of fire deaths, often igniting upholstered furniture and mattresses. The heat transfers to the material, causing a slow, unseen smoldering that can eventually erupt into a full-scale fire. Beyond the risk of fire, direct skin contact with the cherry causes immediate thermal injury. Although the heat source is small, the temperature is high enough to cause deep burns that can penetrate beyond the top layer of skin, leading to permanent scarring.