SOUTHWEST ASIA -- The temperatures are rising at an undisclosed location in Southwest Asia, and most Airmen will usually admit that it is getting hot.

"I've started putting my water bottles in the freezer so that they don't go warm five minutes after I come out to the flightline," one Airman said to his coworker, as they walked out of the flightline dining facility on their way to work after lunch. "It's starting to get really hot out there!"

But what if that Airman's hot isn't officially hot?

According to Master Sgt. Nicky Brown, 386th Expeditionary Operation Support Squadron Weather Flight flight chief, official hot all depends on what the wet bulb globe temperature says.

"There are three different aspects to the computation of the WBGT: Natural Web Bulb Temperature, Globe Temperature and Air Temperature," said Brown, a Williamston, N.C., native deployed from the 374th Operations Support Squadron, Yokota Air Base, Japan. "These three aspects are then converted to five heat stress levels: white (no) flag, green flag, yellow flag, red flag and black flag. There are many days where the temperature will reach 105 degrees Fahrenheit, but if we are gusty and dry we will barely reach 75 degrees for the WBGT."

But how can 105 degrees be only 75 degrees?

It's all based on a formula weather experts use for the WBGT, said Brown: WBGT = (0.7 x natural WBT) + (0.2 x globe temperature) + (0.1 x air temperature).

To help combat the confusion, Brown said, take a look at the parts:

- Natural WBT deals with the humidity in the air; the higher the humidity, the higher the heat stress. During a dry, hot day, a person keeps cool because air is evaporating sweat. When it's humid, a person isn't able to cool off as easily because the moisture in the air keeps the sweat from evaporating as fast. This is why 88 degrees in Biloxi, Miss., has a higher heat stress level than 88 degrees in Phoenix, Ariz., according to the WBGT.

- Globe temperature basically lets someone know how much they are being warmed through the sun's radiation. And since that radiation is strongly influenced by wind speeds, the two are frequently working against each other.

- Air temperature (also called dry-bulb temperature) is just that; the temperature felt while outside.

"It is complicated and can be very confusing," Brown admits. "I know we get plenty of calls about it from people who don't understand. Basically it would take a very hot, humid, stagnant day to reach Heat Stress Stage 5."

So be prepared and keep water nearby - it's getting hot out there.