You can experience hypercapnia when your blood cannot exchange CO2 by Oxygen at the respiratoty bronchial alveoles.    From Wordnik.com.  [Unthreaded #12 « Climate Audit] Reference

Someone who says things like "Carbon Dioxide is harmless" when in fact, hypercapnia can kill people, is a dangerous person.    From Wordnik.com.  [Fellow Republicans urge Bachmann not to boycott 2010 Census] Reference

Above 5% in the atmosphere will cause hypercapnia, above 7%-10% unconsciousness pretty quickly, at least according to the wiki.    From Wordnik.com.  [Unthreaded #12 « Climate Audit] Reference

High levels of CO2 can give rise to hypercapnia and respiratory acidosis, which can lead to unconsciousness and death if left untreated.    From Wordnik.com.  [On Thursday, the Legg report will be published along with...] Reference

Well, hypercapnia means an increase in the frequency of inhalation-exhalation cycles motivated by scarcity of Oxygen in a given environment saturated by CO2.    From Wordnik.com.  [Unthreaded #12 « Climate Audit] Reference

According to other sources, symptoms of mild hypercapnia might include headache, confusion and lethargy.    From Wordnik.com.  [An Englishman's Castle] Reference

Symptoms and signs of early hypercapnia include flushed skin, full pulse, extrasystoles, muscle twitches, hand flaps, reduced neural activity, and possibly a raised blood pressure.    From Wordnik.com.  [An Englishman's Castle] Reference

The spacewalker never experienced any symptoms of hypercapnia, which include headaches, confusion and lethargy, and he said Thursday he was surprised when the spacewalk was called off.    From Wordnik.com.  [Breaking News: CBS News] Reference

Be especially cautious if you have chronic obstructive pulmonary disease or a condition that reduces oxygen to the tissues (hypoxia) or causes an excess of carbon dioxide in the blood (hypercapnia).    From Wordnik.com. Reference

At which point we’ll all be dead from hypercapnia anyway.    From Wordnik.com.  [Unthreaded #20 « Climate Audit] Reference

Just stop your breathing and you’ll go into a hypercapnia condition.    From Wordnik.com.  [Unthreaded #12 « Climate Audit] Reference

“very high concentrations of atmospheric CO2 can produce a state of hypercapnia, or an excessive amount of CO2 in the blood, which typically results in acidosis, a serious and sometimes fatal condition characterized in humans by headache, nausea and visual disturbances.”.    From Wordnik.com.  [Unthreaded #12 « Climate Audit] Reference