igh temperatures in Puerto Rico and surrounding islands on Wednesday felt even hotter and raised the heat index to 125 degrees.
Puerto Rico endured temperatures that felt as hot as 125 degrees Fahrenheit this week, according to the National Weather Service, as the U.S. territory experiences excessive heat conditions that will continue for another week.
The tropical island already experienced record-breaking minimum and maximum temperatures for this time of year on Monday (79 degrees Fahrenheit) and Tuesday, when it jumped to 95 degrees. But the heat index, which measures how temperatures feel like to the human body, surpassed 120 degrees Fahrenheit on Tuesday in parts of Puerto Rico, even peaking to 125 in the northern towns.
The combination of a low-pressure system near Florida and a high-pressure system just east of Puerto Rico has essentially formed a “heat dome” that has remained stuck in the same place for various days, John Morales, a certified consulting meteorologist at ClimaData and a hurricane specialist for NBC Miami, told NBC News.
A combination of dry air, unusually warm ocean waters and high humidity is causing people to feel the heat more severely.
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The National Weather Service usually issues a heat advisory when the heat index reaches or exceeds 105 degrees Fahrenheit, "so when it's 125, that's incredibly dangerous," Morales said.
The combination of high humidity and high temperatures can be dangerous because, when the humidity in the air is high, less sweat can evaporate off the human body to cool it off.
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