While itself varying, such change must be taken into account when designing a system for overall behavior to stimuli or likely environmental conditions, and in particular the worst-case conditions encountered under the high stresses imposed near the limits of operability— for example, an air-cooled engine in a desert climate on a very hot day.
When creating a system that responds to various stimuli or environmental factors, it's essential to take into account variations that may occur. This is especially crucial when designing for extreme conditions, such as those encountered near the limits of operability— consider, for example, an air-cooled engine operating in a scorching desert climate on a sweltering day.