What are the physical effects of carbon monoxide poisoning if you survive?

Active tissue death: Carbon monoxide causes its toxic effects by preventing the effective transport of oxygen, and as such causes damage to tissue that is highly metabolically active (and requires more oxygen to stay alive). This leads to strokes, heart damage, and kidney damage. Chronic low-level exposure can lead to cognitive problems, increased cardiovascular risk, and other issues.

Depends on dose: The long term effects of co poisoning depend on the dose and duration of exposure. Exposure to small doses at the lower limits of toxicity (35 parts per million for 8 hours) may cause only mild symptoms while higher doses (> 200 ppm) may have long term consequences. See this page for more details: http://biology.About.Com/od/molecularbiology/a/carbon_monoxide.Htm.