What is indicated by the air temperature measured by a thermometer with a wet sock evaporating into a rapid stream of air?

The air temperature measured by a thermometer with a wet sock evaporating into a rapid stream of air is indicative of the wet bulb temperature. The wet bulb temperature reflects the cooling effect of evaporation and is determined by the combination of air temperature and humidity. When water evaporates from the sock, it absorbs heat from the air, cooling the thermometer and providing a measurement that accounts for both temperature and moisture content in the air.

This measurement is essential in various applications, such as determining comfortable indoor conditions and understanding the cooling capacity of evaporative cooling systems. It is particularly useful in assessing the potential for heat-related illnesses, as it indicates the effectiveness of sweat evaporation under specific environmental conditions.

Other options, like dry bulb temperature, indicate the standard air temperature without considering moisture, while relative humidity refers to the amount of moisture in the air compared to what it can hold at that temperature. The thermal comfort index incorporates additional factors and does not directly measure temperature like the wet bulb thermometer does.