Runners gather outside Trader Joe's in Back Bay before the start of the Speedo Santa Run on Saturday, Dec. 14, 2013. (Credit: WBZ-TV)
2013 Speedo Santa Run
Runners in high spirits before the start of the 2013 Speedo Santa Run in Back Bay. (Credit: WBZ-TV)
2013 Speedo Santa Run
And they're off! Runners begin the Speedo Santa Run in Back Bay on Saturday, Dec. 14, 2013. (Credit: WBZ-TV)
2013 Speedo Santa Run
Boston Police Department motorcycle officers get ready to escort runners at the start of the Speedo Santa Run in Back Bay on Saturday, Dec. 14, 2013. (Credit: WBZ-TV)
2013 Speedo Santa Run
The first Speedo Santa Run in 2000 featured five guys wearing nothing but Santa hats and Speedos. Costumes for the event have become more elaborate. (Credit: WBZ-TV)
2013 Speedo Santa Run
One of the highlights of the annual Speedo Santa Run is runners who like to horse around. (Credit: WBZ-TV)
2013 Speedo Santa Run
Runners had to brave temperatures in the teens during the Speedo Santa Run on Saturday, Dec. 14, 2013. (Credit: WBZ-TV)
2013 Speedo Santa Run
The annual Speedo Santa Run in Back Bay is wheel-chair accessible. Since it began in 2000, the event has raised more than $1.4 million for needy children in Boston. (Credit: WBZ-TV)