Final answer:
The heat and humidity needs depend on temperature regulation through sweat evaporation, which is affected by the humidity levels in the air, with humid days impeding evaporation and very low humidity causing mucous membrane issues.
Step-by-step explanation:
The amount of heat and humidity a patient needs depends on the body's mechanism for regulating temperature through the evaporation of sweat and water from the skin and respiratory passages. On hot, dry days, the evaporation of sweat cools the body efficiently; however, on humid days, the higher concentration of water vapor in the atmosphere reduces the evaporation rate from the skin's surface, making the body feel hotter. Conversely, very low humidity can cause discomfort from the excessive drying of mucous membranes and increase the risk of respiratory infections.