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Boston Marathon weather forecast will be warm, but how hot is too hot to run?

High temperatures could put Boston Marathon runners at risk for hyperthermia
High temperatures could put Boston Marathon runners at risk for hyperthermia 01:13

BOSTON - The Boston Marathon weather forecast for Monday sounds glorious for spectators, but it may be too hot for the runners.

Those preparing to run the race are probably feeling somewhat apprehensive. According to experts, ideal marathon temperatures are between 46 and 59 degrees, so temperatures in the high 60s are considered "hot."

What happens to marathon runners in the heat?

Running in higher temperatures is not only uncomfortable but can raise a runner's core body temperature leading to hyperthermia. Mild to moderate hyperthermia can cause muscle cramps, abdominal cramps, lightheadedness, headache, nausea and vomiting, and clammy skin.

But as it progresses, hyperthermia can lead to confusion, seizures, organ failure, and death. Generally, a body temperature above 104 degrees is considered severe hyperthermia.

What should runners do if they overheat?

Any runner who begins to develop symptoms of overheating needs to stop, rest, and if still feeling ill, get to one of the medical tents along the route. There, depending on the severity of their symptoms, health care staff will place them in a cool, shaded area, remove their excess clothing, apply ice packs, have them sip cooled drinks or administer intravenous hydration, draw blood, and if their body temperature is dangerously high, submerge them in an ice bath.

How marathon runners can prevent overheating

There are some steps runners can take to try to prevent overheating while running.

  • Hydrate well before the marathon and continue to drink water and rehydration solutions throughout the race.
  • Avoid alcohol, caffeine, and medications like antihistamines that can be dehydrating.
  • Wear lightweight and light-colored clothes
  • Wear sunscreen
  • Slow down and pace yourself (do not try to achieve your personal best)
  • Pour water over your head while running

Hottest Boston Marathons

Back in 2017, temperatures reached the mid-70's during the Boston Marathon and about 20 runners ended up with dangerously high body temperatures and had to be put into ice baths. One runner had a body temperature of 108.8 degrees!

In the 2012 Boston Marathon, the 80-degree heat forced more than 4,000 runners to drop out of the race, including the defending men's and women's champions.

"The heat affects everybody. Nobody runs fast in the heat. Nobody benefits from the heat," 1968 winner Amby Burfoot told the Associated Press back in 2012. "It's just the worst thing a marathoner can face."

The 1976 Boston Marathon become known as the "Run for the Hoses" because it was held in 100-degree heat.

"I hate that the marathon is such a crapshoot. You train for 4-6 months, and the only thing that matters is the weather," Burfoot told the AP. 

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