What can be a symptom of exposure to smoke in the cockpit?

Exposure to smoke in the cockpit can lead to a variety of physiological responses due to the inhalation of harmful particles and gases present in smoke. One significant symptom that may arise is irregular heartbeats. This can occur as a result of the body reacting to the stress of smoke inhalation, which may cause hypoxia (lack of oxygen) or irritate the cardiovascular system, leading to arrhythmias.

The mechanism behind this can involve the stimulation of the sympathetic nervous system due to smoke exposure, which can disrupt normal heart rhythm and function. Furthermore, the effects of smoke on the respiratory system can lead to reduced oxygen levels in the blood, further contributing to cardiovascular instability.

In contrast, the other choices do not typically connect to smoke exposure in the cockpit. For instance, weight gain is not an immediate response to smoke inhalation; increased vision clarity is counterintuitive since smoke can obstruct vision; and loss of smell does not directly correlate with cockpit smoke exposure in the way that irregular heartbeats do. Thus, the link between smoke inhalation and cardiovascular symptoms, especially irregular heartbeats, underscores the potential dangers faced by pilots in such situations.