[en] High temperature (T equal or greater than 10⁸⁰K) CNO cycle burning is studied. An overabundance of both ¹⁷O and ¹⁸O after times of approximately 10² seconds are found. For temperatures of 150 and 200 million degrees it is found that the ¹⁸O abundance is much larger than the ¹⁷O abundance after burning times of about 10³ seconds. Known uncertainties in the nuclear reaction rates do not alter the conclusions. The effects of mixing various amounts of hydrogen-rich material into the intershell convection region of red giants undergoing helium shell flashes were examined. It was found that significant amounts of ¹⁴C can be produced via the ¹⁴N(n,p)¹⁴C reaction. If substantial portions of this intershell region are mixed out into the envelopes of red giants then ¹⁴C may be detectable in evolved stars such as IRC 10216. A neutron number density in the intershell region of approximately 10¹⁵ -- 10¹⁷ cm^-3 and a flux of approximately 10²³ -- 10²⁵ cm^-3 sec^-1 is found. This neutron flux is many orders of magnitude above the flux required for the classical s-process and thus an intermediate neutron process (i-process) may operate in evolved red giants. The neutrons are principally produced by the ¹³C(α,n)¹⁶O reaction. In all cases studied one finds substantial enhancements of ¹⁷O. These mixing models offer a plausible explanation of the observations of enhanced ¹⁷O in the carbon star IRC 10216. For certain physical conditions one finds significant enhancements of ¹⁸O and ¹⁵N in the intershell region