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As high temperatures set new records, it's more important than ever to be aware of heat's threat to our health

As we read in the news on a daily basis, triple-digit temperatures are now the new (ab)normal. Areas of the US and Europe that are heavily populated are experiencing levels of heat that they're not built to sustain. Electrical grids are barely keeping up with the demand for constant air conditioning in the US, but we forget that in most of the world, AC is a luxury, and so is the power needed for it. 

What's most disturbing is that the large majority of people are not used to heat like this, and aren't used to planning or watching for warning signs of heat exhaustion or heat stroke. 


A good example of this is the number of deaths among visitors to national parks in recent weeks. People are simply not used to calculating how hot it really is out there, and if they'll be able to sweat. Temperatures may seem bearable, but when humidity also climbs, we're unable to sweat and cool our bodies. That's when heat strokes most often happen and that's why it's important for people to look up the heat index wherever they plan to be, whether outdoors or indoor. The heat index is a combination of temperature and humidity, (sort of the opposite of windchill), and it gives us a better sense of how risky the temperatures we're seeing really are. The map below, shows us the heat-index temperatures for today.


Heat index maps are actually very hard to find (the one above is produced by the Climate Change Institute at the University of Maine). These are by no means the worst temperatures we've seen so far. People are not used to watching out for symptoms of heat exhaustion and heat stroke, and yet these conditions are life threatening. In fact, the symptoms are often ignored as "a simple headache" or "just a cramp," and even health care workers fail to diagnose heat-related deaths as a result. But what is causing the extreme heat? The asnwer is manmade cimate change, combined with a natural shift in a global climate pattern known as El Niño Southern Oscillation (or ENSO).


How the El Niño climate pattern affects different regions of North America. For the past several years we've been in the cooler phase known as La Niña, but we're now shifting to El Niño, which brings much warmer temperatures to much of the US.

As shown in the image above, El Niño brings warmer air from the Pacific to the continental US. Until this summer, we've been in a phase nicknamed La Niña, which is substantially cooler. We're currently in a transition period between the two, with heat extremes affecting almost all regions. These temperatures in the US and Europe would not be possible without manmade climate change, and we expect that they will become very common in coming years, as shown in the map below.

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Prediction of how many days above 90º F will be experienced by regions of N. America if we continue producing greenhouse gas emissions at the rate we currently are. Most of the US South, Southwest and California will have constant temperatures above 90º for one third to more than a half of the year.

A similar fate is in store for developing countries around the world, as well as Europe, all of which have much less access to air conditioning. This makes the need for heat abatement technology that does not use energy an essential solution to the climate crisis.

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