Carbon Monoxide Poisoning? That doesn't sound good.

Signs and symptoms

Carbon monoxide is toxic to all aerobic forms of life. It is easily absorbed through the lungs.[5] Carbon monoxide is colorless, odorless, tasteless, and non-irritating, which makes it difficult for humans to detect.[5] Inhaling even relatively small amounts of the gas can lead to hypoxic injury, neurological damage, and even death. Different people and populations may have a different carbon monoxide tolerance level.[6] On average, exposures at 100 ppm or greater is dangerous to human health.[1] In the United States, the OSHA limits long-term workplace exposure levels to less than 50 ppm averaged over an 8-hour period;[7][8] in addition, employees are to be removed from any confined space if a upper limit ("ceiling") of 100 ppm is reached.[9] Carbon monoxide exposure may lead to a significantly shorter life span due to heart damage.[10] The carbon monoxide tolerance level for any person is altered by several factors, including activity level, rate of ventilation, a pre-existing cerebral or cardiovascular disease, cardiac output, anemia, sickle cell disease and other hematological disorders, barometric pressure, and metabolic rate.[11][12][13]

The acute effects produced by carbon monoxide in relation to ambient concentration in parts per million are listed below:[14][15]
Concentration Symptoms
35 ppm (0.0035%) Headache and dizziness within six to eight hours of constant exposure
100 ppm (0.01%) Slight headache in two to three hours
200 ppm (0.02%) Slight headache within two to three hours; loss of judgment
400 ppm (0.04%) Frontal headache within one to two hours
800 ppm (0.08%) Dizziness, nausea, and convulsions within 45 min; insensible within 2 hours
1,600 ppm (0.16%) Headache, tachycardia, dizziness, and nausea within 20 min; death in less than 2 hours
3,200 ppm (0.32%) Headache, dizziness and nausea in five to ten minutes. Death within 30 minutes.
6,400 ppm (0.64%) Headache and dizziness in one to two minutes. Convulsions, respiratory arrest, and death in less than 20 minutes.
12,800 ppm (1.28%) Unconsciousness after 2-3 breaths. Death in less than three minutes.