Final answer:
Ambient temperature is not used to determine the upper limits of exercise intensity in cardiac rehabilitation. Instead, factors like body temperature, perceived exertion, and cardiac reserve are considered.
Step-by-step explanation:
The recommended upper limits of exercise intensity during inpatient cardiac rehabilitation are determined by several factors but not by ambient temperature. Factors such as body temperature do significantly affect heart rate (HR) and stroke volume; however, ambient temperature is not directly used to set exercise intensity limits.
Body temperature impacts cardiac function, where hyperthermia (elevated body temperature) increases HR and strength of contraction, and hypothermia (lowered body temperature) slows the rate and strength of heart contractions. The heart's ability to endure and adapt to increased demands is linked to the concept of cardiac reserve, highlighting the difference between maximum and resting cardiac output (CO). In clinical settings, variables such as perceived exertion and pain are assessed using scales like the Rating of Perceived Exertion (RPE) and pain scales to understand a patient's exertion and discomfort levels.