What are the symptoms of carbon monoxide poisoning?

death and you go very pink looking apparently

Headache
Dizziness
Nausea
Flulike symptoms, fatigue
Shortness of breath on exertion
Impaired judgment
Chest pain
Confusion
Depression
Hallucinations
Agitation
Vomiting
Abdominal pain
Drowsiness
Visual changes
Fainting
Seizure

Death if not attended to asap. CO2 is odourless and weakness and resporatory problems. Sleepiness id usually the first symptom. Not to be taken lightly/ if suspected call you gas company

sitting very still in a chair with your eyes open and not responding to your name.

Acute
The earliest symptoms, especially from low level exposures, are often non-specific and readily confused with other illnesses, typically flu-like viral syndromes, depression, chronic fatigue syndrome, and migraine or other headaches.[13] This often makes the diagnosis of carbon monoxide poisoning difficult. If suspected, the diagnosis can be confirmed by measurement of blood carboxyhemoglobin.

The main manifestations of poisoning develop in the organ systems most dependent on oxygen use: the central nervous system and the heart. The clinical manifestations include tachycardia and hypertension, and central nervous system symptoms such as headache, dizziness, confusion, convulsions, and unconsciousness. CO poisoning may also produce myocardial ischemia, atrial fibrillation, pneumonia, pulmonary edema, hyperglycemia, muscle necrosis, acute renal failure, skin lesions, visual and auditory problems, and respiratory arrest.[14]

One of the major concerns following CO poisoning is the severe neurological manifestations that may occur days or even weeks after an acute poisoning. Common problems encountered are difficulty with higher intellectual functions and short-term memory, dementia, irritability, gait disturbance, speech disturbances, parkinson-like syndromes, cortical blindness, and depression[15] (depression can occur in those accidentally exposed). These delayed sequelae occur in approximately 15 percent of severely poisoned patients after an interval of 2 to 28 days. It is difficult to predict who may develop delayed sequelae; however, advancing age, loss of consciousness while poisoned, and initial neurological abnormalities may indicate a greater chance of developing delayed symptoms. According to the Philadelphia poison control hotline, sequelae are generally not anticipated when exposure is not severe enough to result in loss of consciousness.


[edit] Chronic
Long term, repeat exposures present a greater risk to persons with coronary heart disease and in pregnant patients.[16] Chronic exposure may increase the incidence of cardiovascular symptoms in some workers, such as motor vehicle examiners, firefighters, and welders. Patients often complain of persistent headaches, lightheadedness, depression, confusion, and nausea. Upon removal from exposure, the symptoms usually resolve themselves.[17]

drowsiness and unable to think straight.
redness of the skin is a sign of it

A good sign to look out for (which is how I knew we had a leak) is red lips. My lips were really red as if I had put lipstick on. Also headaches, which ease when you leave the house (or wherever it is that has a leak) and flu like symptoms

Headaches red eyes, and look for sut around the house make sure all flues and vents are open

Source: Exhaust fumes of motor vehicles. Smoke from most fires. Back-draughts from blocked chimney flues. Emissions from defective gas or paraffin heaters.

Effects:
Prolonged exposure to low levels: Headache. Confusion. Aggression. Nausea and vomiting. Incontinence.

Brief exposure to high levels: Grey-blue skin colouration with a faint red tinge. Rapid, difficult breathing. Impaired consciousness, leading to unconsciousness.