http://www.videung.se/cold_effects.htm#

Above is a handy windchill calculator.

Unfortunatly temperature is only in celsius and wind in meters per second.

On the left temperature meter you click current temp in C
On the middle wind meter you click current wind in meter per second.

Than the right hand windchill meter will automatically show what the windchill reading is.

That's a handy visual tool. Might have to translate the web page to get the full benefit.

Here is an English version of the Environment Canada's calculator. The coldest I've ever experienced is -57*C (-71*F). That's VERY cold! You learn the value of layers real quick!
Wind Chill Calculator

But we Canadians don't just get cold, we also experience some pretty warm temps, so we designed the Humidex which is a bit different from the heat index the US uses. My max temp experienced was 48*C (118*F) which is not as hot as some places in the US but its still well above my "melting" point!
Humidex Calculator