The heat index/humidex combines temperature and humidity into one number to reflect apparent temperature. It is a measure of how the air ”feels”. As humidity increases, heat index goes up and the sensation of heat increases. For instance, a temperature of 31°C ”feels like” 51°C when the humidity is 85%.
Windchill considers the combined effect of wind and temperature on what we ”feel”. When the wind ”speed” increases, the ”boundary layer” (a thin layer of air which warms our bodies), is taken away, our skin temperature drops, and we feel colder.
This kit includes an anemometer with built in temperature/humidity sensor that transmit data up to 100 feet.