Final answer:
Latent heat is crucial in the humid tropics due to the cooling effect of water evaporation, limiting temperatures to about 35°C (95°F). In the arid tropics, sensible heat is more important, with extreme temperature fluctuations due to low humidity, leading to high daytime temperatures and cold nights.
Step-by-step explanation:
The heat that is most important in the humid tropics is latent heat associated with the evaporation of water, which helps to limit high temperatures. Because the humid tropics have a high concentration of water vapor in the air due to the presence of numerous bodies of water, evaporation consumes a significant amount of heat, which has a cooling effect on the environment.
In contrast, the arid tropics, such as the Sahara and Namib deserts, experience extremely high temperatures and significantly lower humidity. Here, evaporation rates are high due to the dry air and lack of water sources, yet the absence of significant water vapor means there's little to retain the heat during the night.