For general-purpose transistors, IC is measured in milliamperes, while ICO is measured
in microamperes or nanoamperes. ICO, like Is for a reverse-biased diode, is temperature
sensitive and must be examined carefully when applications of wide temperature
ranges are considered. It can severely affect the stability of a system at high
temperature if not considered properly. Improvements in construction techniques have
resulted in significantly lower levels of ICO, to the point where its effect can often be
ignored.