madmechanic started a thread about car thermometers/thermistors that gave me an idea. Thanks for that!
https://www.marketforum.com/forum/topic/36235/
https://en.wikipedia.org/wiki/Temperature_measurement
Many methods have been developed for measuring temperature. Most of these rely on measuring some physical property of a working material that varies with temperature. One of the most common devices for measuring temperature is the glass thermometer. This consists of a glass tube filled with mercury or some other liquid, which acts as the working fluid. Temperature increase causes the fluid to expand, so the temperature can be determined by measuring the volume of the fluid. Such thermometers are usually calibrated so that one can read the temperature simply by observing the level of the fluid in the thermometer. Another type of thermometer that is not really used much in practice, but is important from a theoretical standpoint, is the gas thermometer.
Other important devices for measuring temperature include:
Related to this is how we determine the "heat index" or the temperature that it feels like. The chart below uses humidity, which is dependent on the temperature because warmer air holds more moisture(60% humidity at 80 degrees is just a bit humid with a dew point around 65 deg. and makes it feel just 2 degrees warmer but 60% humidity at 98 deg. F has a dew point of 82 deg. which would be at the extreme highest level on the planet and make it feel 15 degrees hotter.....dangerous heat. 
I actually prefer using the dew point rather than the humidity because it's an independent variable vs the humidity which is dependent on the temperature as noted above. On the chart below, they don't have dew points of less than 60 deg. F because when the air is that dry, evaporation of moisture/sweat is very efficient at cooling and the air temperature does not feel any warmer to the human body.
http://thevane.gawker.com/this-is-why-the-heat-index-is-so-important-1609195413
One can ascertain the dew point by plugging in the temp and humidity here:
http://thevane.gawker.com/this-is-why-the-heat-index-is-so-important-1609195413
Note the difference the dew point(moisture in the air) makes when comparing heat index/feels like temperatures with high dew points and low dew points.
Chillicothe, MO at 94 degrees felt 7 degrees hotter(114 deg. F) than it did at Phoenix AR, even though Phoenix had an actual thermometer reading that was 18 degrees hotter at 112 deg. F, while feeling like "just" 107 deg. F.
According to Wunderground, on July 13, 1995 Appleton, Wisconsin saw what is probably the highest heat index ever recorded in the United States. The air temperature reached 101°F and the dew point hit an astounding 90°F, leading to a heat index of 148°F. The article also notes that the "absolute highest dew point" ever recorded in the world was 95°F in Dhahran, Saudi Arabia, which, with an air temperature of 108°F, produced a "theoretical" heat index of 176°F.
Here are a couple of maps that I show on our daily weather page on the trading forum:
I'm going to have to re-read this all several times to understand the information being presented but based on my first couple attempts it sounds interesting and important to understand.
Thanks Mike!