Heat indices will hit dangerously high levels this weekend in the Triangle

Heat indices will hit dangerously high levels this weekend in the Triangle, as the entire East Coast gets hit by a heat wave .

Why it matters: It's the first dangerous heat wave of the year, and it is coming earlier than usual, Axios' Andrew Freedman writes .

• It also brings heightened risks for the very young and elderly and those with chronic health conditions.

Driving the news: Heat index values , or what the outside temperature feels like to the human body, will hit between 103 to 105 in Raleigh and Durham this weekend, according to the National Weather Service's Raleigh office.

• The NWS said it is categorizing this weekend's heat as a major heat risk — though parts of the Midwest will see extreme risks.

What they're saying: Andrew Kren, a meteorologist for the National Weather Service's Raleigh office, said in a weekly briefing that people without effective means of cooling or adequate hydration will be most vulnerable for health risks.

• "You'd want to cancel any outdoor activities during the heat of the day, stay hydrated and stay in a cool place as well as check in on friends and neighbors," he said.

The heat wave , he added, is likely to continue past the weekend. There is a 50% to 70% chance for above-normal temperatures through the end of the month.

The big picture: Long-duration heat waves affect more than our health. They can weigh on economic productivity and potentially weaken infrastructure.

• Studies have shown that economic productivity takes a hit during extreme heat events and that climate change is likely to worsen these impacts in the future.
• Some research even suggests that outdoor workers' injury rates increase in hotter temperatures.
• It also can lead to infrastructure malfunctions, from power outages to the melting of airport tarmacs .