Describe an important non-pharmacological intervention in IMCI for respiratory illnesses.

Encouraging increased fluid intake is a critical non-pharmacological intervention in the IMCI framework for managing respiratory illnesses. This approach helps to prevent dehydration, which can be a complication of respiratory infections that often lead to fever and increased respiratory rates. Adequate fluid intake supports the body's efforts to clear mucus from the airways, thus potentially easing symptoms and aiding recovery. It also helps to maintain optimal physiological functions, which is essential in the context of illness.

While the use of humidifiers can be beneficial in certain cases by adding moisture to dry air and helping to soothe irritated respiratory passages, it is not universally applicable or necessary in all situations. Regular physical exercise may generally contribute to overall health but is not appropriate as an immediate intervention during acute respiratory illness. The application of warm compresses, while it can provide comfort in certain contexts, does not directly address the underlying issues related to respiratory diseases. Thus, promoting increased fluid intake stands out as a vital and immediately helpful strategy within the IMCI approach to managing respiratory illnesses in children.