Some unexpected consequences of extreme heat

This weekend, nearly 200 million Americans will face temperatures of 32 ° C (90 ° F) and above. Add to that the humidity and many cities on the East Coast and Midwest will feel closer to 110F (43C).

Heat waves have killed more people on average than any other extreme weather event in the United States, according to the Centers for Disease Control (CDC).

The authorities define extreme heat as a period of high heat and humidity of two to three days with temperatures above 32 ° C (90 ° F).

After the hottest June ever recorded, the US National Weather Service (NWS) estimates that more than 100 record minimum temperatures could be established, as the heat may persist even after sunset.

Here's what this type of heat can do.

1. Air conditioners make cities hotter

According to a report published in 2018 by the US Energy Information Administration (EIA), air conditioning is used in 87% of US households. During heat waves, the use of air conditioning heavily solicits power grids and can cause breakdowns at the city scale.

In the cities, this means that millions of units – including those of cars, buses and trains – constantly emit heat into the atmosphere. Studies have shown that the extra heat produced by air conditioning can raise the temperature by 2 ° C. And when it gets warmer, our thermostats go down and the cycle continues.

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But that goes further than an increasingly hot summer season: emissions from air conditioners and their refrigerants contribute to climate change. The synthetic greenhouse gases used in air conditioners, called hydrofluorocarbons (HFCs), are thousands of times more powerful than carbon dioxide in the atmosphere.

In cities, the cycle, concrete, asphalt, steel and glbad exacerbate the cycle, creating an urban heat island.

2. Aircraft can not take off

When temperatures get too high, the planes get grounded.

Extreme heat reduces the density of the air and the amount of lift that an airplane can get to take off. Temperatures of 120F (49C) saw dozens of flights canceled in Phoenix during a heat wave in 2017.

The smaller aircraft are hit first, but the larger Boeing or Airbus aircraft have maximum operating temperatures of about 126 ° F (52 ° C), according to AZ Central.

3. Roads can melt or explode

In a heat wave, concrete and asphalt do not go well.

The asphalt is deformed and melts. Concrete, if water is involved, can sometimes explode or break.

This week, local Kansas media reported several cases of roads cracked and deformed by rising temperatures.

In Iowa, a mayor of a city said that old concrete roads soaked with floodwater this spring were exploding and damaging the sewer pipes.

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4. Cookies cook in cars

The NWS outpost in Omaha, Nebraska, has demonstrated how hot vehicles can be in hot weather by cooking American biscuits on the fly.

Temperatures have reached a maximum of 85 ° C (185 ° F) – not enough for proper baking, but certainly too hot for humans or animals to survive.

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• Children left in hot cars

According to the National Meteorological Service, 21 young children died in hot cars this year.

5. The metal gets even hotter

Not surprisingly, while everything is warming up during a heat wave, anything that is metal gets even hotter.

As far as the power lines are concerned, this can cause dangerously low sagging. If the lines fall low enough to touch the ground or trees, they may short-circuit.

Knots can form on the rails of the train as the metal expands. In 2012, a "thermal break" caused the derailment of a 32-car freight train and its crossing of the overpbad; a similar derailment occurred in 2017. Experts told Fox 26 News that more than 2,100 trains had derailed in the last 40 years because of these thermal heats.

Metal components in drawbridges can expand and become unusable – last year, Chicagoirefighters had to water a drawbridge from downtown so that it can be used.

6. Agriculture takes a hit

Cultures can also feel the heat.

Midwestern farmers are warning that vegetables may be wilting in heat and that farms will lose productivity, which will worsen the situation after a historic flood season this spring.

Soybean producers also say that drought could lead to an increase in the number of mites and other plant diseases.

7. Smog worsens

Extreme heat exacerbates pollution, which can be dangerous for the very young, the elderly and people with respiratory diseases.

In the nation's capital, where the mayor has declared a thermal emergency, officials warned that air quality would reach unhealthy levels for these sensitive groups over the weekend.