Don't let these Santa's fool you ... they're freezing their asses off.
More than 100 runners braved the 30 degree Boston temp Saturday to participate in the 2017 Santa Speedo Run.
Lucky for them ... the run coincided with the first snowfall of the looming Winter season.
The run is for charity and they did well, raising more than $76,000 for the PlayBall Foundation, which benefits local children in need. The charity makes sports activities available for middle school students in the Boston area.