If you are looking for a way to determine your latitude and longitude go to the find location page. where ddd = 1-3 digits for degrees, mm = 2 digits for minutes, ss = 2 digits for seconds and D = N,S,E, or W. The seconds and special characters (spaces, apostrophes, quotes) are all optional in this format.
When there is a low level of carbon dioxide in the blood, the blood will be alkaline in nature. This will lead to the blood vessels of the body constricting, thus reducing the flow of blood in the body.
Thus, CO2 stops leaving your blood faster if the lungs are empty, meaning the CO2 levels in your blood reach critical faster and you need to breath sooner. Oxygen levels in your blood are likewise not rising fast enough (or at all, since you just exhaled), but it's the rise in CO2 that makes you gasp.