"A bystander witnessed him collapse," department spokeswoman Maria Hogg said.
The citizen called 911 at 9:37 a.m., and officials said it was too soon to know whether the man—and two others who went into cardiac arrest shoveling snow in the hours that followed—would survive.
The two additional cardiac arrests were in Columbia, Hogg said.
"We urge you to not overexert yourself," the department advised. "Take breaks, hydrate, ask for help!"
Here are some additional tips from Howard County Department of Fire & Rescue Services:
- Shovel a little at a time—this is a heavy, wet snow.
- Take breaks.
- Keep your cell phone on you outside in case of emergency.
- Tell family/friends when you will be outside.