Imagine that it is so hot that you have to create a new word to describe the day. That's exactly what happened in Japan.

Three cities in central Japan – Tajimi, Gujo and Toyoda – each topped 40°C (or 104°F) on Tuesday.

Those were the first three cities to mark days categorized as “kokushobi” – or “cruelly hot days” – since the Japanese Meteorological Agency coined the term after a public vote earlier this year. It is pronounced: koh-koo-shoh-bee.

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The new category is meant to bring more awareness to the heat and to hopefully lessen the number of cases of heat stroke and heat exhaustion in the country.

Kokushobi tops the scale of words to describe heat in Japan, followed by mōshobi, manatsubi and natsubi. Mōshobi, an extremely hot day, was added in 2007. This July alone, there have been 278 locations that have recorded Mōshobi. Well over 700 communities reported manatsubi, or a midsummer day.

The hot weather comes amid sinking air from a strong heat dome located over the western Pacific Ocean. Several days this week will feature at least daily record highs.

At least 260 people were taken to the hospital on Tuesday with heat stroke symptoms around Tokyo and emergency dispatches surpassed 3,400, according to Kyodo News.

Climate change leads to more cruelly hot days

These cruelly hot days are becoming more common as our climate warms.

Climate change made Tuesday's extreme temperatures five times more likely when compared to a world without human-caused carbon pollution.

Japan's national hottest temperature record was set just last year in Isesaki when it hit 41.8°C (or 107.2°F) on August 5. It was the second time that Japan had hit a new national record last summer.

Some 14 stations would have recorded kokushobi conditions on that day. A total of 30 stations would have met the threshold to be a "cruelly hot day" last summer.

Over 1,800 suffered heat strokes in their workplace last year in Japan, a record high, and 19 died, according to Japanese officials.

For the first time, workers are being encouraged to wear T-shirts and shorts in the office to reduce the use of air conditioning and other energy and to make workers more comfortable.

Jonathan Belles has been a digital meteorologist for weather.com for 10 years. His favorite weather is tropical weather, but also enjoys covering high-impact weather and news stories and winter storms. He's a two-time graduate of Florida State University and a proud graduate of St. Petersburg College.