In addition to the excessive heat brought into Ferguson by the authorities, Mother Nature is bringing some of her own. A dangerous combination of heat and humidity prompted forecasters to issue an Excessive Heat Warning until Sunday for the St. Louis area, including Ferguson.

In stark contrast to what most of the United States has seen this summer, we're entering an all-too-common summertime pattern where a ridge of high pressure sets up over the central part of the country, keeping the weather settled and allowing heat and humidity to build.

The combination of heat and humidity is dangerous because the saturated air makes it hard for the sweat to evaporate off of one's skin, preventing the body from cooling off effectively. The inability to cool off makes that already-hot 100°F reading have the same effect on one's body as a much warmer temperature, which is measured by the heat index. In this case, heat indices could approach 107°F according to the National Weather Service.

The St. Louis area isn't the only region expected to experience a prolonged period of dangerous heat. The image at the top of this post depicts the National Weather Service's predicted heat indices for 3PM on Thursday. Areas in and near the South Carolina Lowcountry will see heat indices approaching 110°F a couple of days this week.

Statistics kept by NOAA show that heat kills more people each year than any other extreme weather event. In order to prevent heat-related illnesses, avoid spending more than a few minutes at a time outdoors during the afternoon, limiting activities to the morning or evening hours.

If you or someone you know is involved with the protests in Ferguson, make sure that you (or they) stay as hydrated as possible. The crowd faces enough problems without having to worry about the added toll taken by the heat.

And for crying out loud, no matter where you live, stop leaving your kids in the car. The temperature in a car can rise to lethal levels in just a couple of minutes on even just a "warm" day, let alone during a heat wave. People who leave their children in the car on a hot day not only have to deal with the crushing guilt of killing their own child, but they'll have plenty of time to relive it over and over while spending many years in prison.

[Images via NWS | h/t Capital Weather Gang]