The snow shovelling deaths of three people in Buffalo, New York, is a grim reminder that rushing to clear snow can be a recipe for a heart attack for some people.

Shovelling snow is a lot more physically demanding than many appreciate. A half hour of tossing aside the white stuff is really the exercise equivalent of lifting weights. Not only can the snow get as heavy as the dumbbells at the gym, those clearing the snow tend to want to work hard and shovel quickly to get back inside.

It's great exercise if you're heart healthy. But for those with known and hidden heart conditions, it can also be fatal.

Winter temps raise the risk

More heart attacks occur in the winter than in the heat of the summer, and the main reason for that is the cold.

Just stepping out into cold air will cause your blood vessels to constrict and for your blood pressure and heart rate to increase. According to the Heart and Stroke Foundation, it also increases the concentration of something called fibrinogen, a protein in our blood involved in clotting. When the cold, the exertion, and the increase in fibrinogen combine, the risk of a heart attack soars.

Who's at risk?

Patients who have a known heart disease condition are obviously at highest risk of a heart attack while shovelling snow. These conditions can include those with an enlarged heart, an arrhythmia, atherosclerosis or angina.

But others who haven't been diagnosed with heart disease can also be at risk. These can include smokers, anyone with a strong family history of heart disease, and those with high blood pressure, particularly if they are middle-aged or older.

The Heart and Stroke Foundation recommends that anyone who has ever had a heart attack, stroke, or heart surgery should have someone else do the shovelling or should speak to their doctor about their shovelling risk.

Knowing the signs

Although chest pain or discomfort is the most common symptom of a heart attack, some people will not experience pain at all. The classic warning signs of a heart attack include:

  • pressure or squeezing in your chest
  • pain radiating down one arm or shoulder
  • shortness of breath or dizziness
  • profuse sweating
  • intense nausea

If any of these occur while shovelling, sit down and rest. If the feeling doesn’t go away in a couple of minutes, call 911.

Reduce the risk

Here are some tips from the Heart and Stroke Foundation and the American Heart Association for reducing your heart risk while shovelling

Don’t shovel after drinking. Alcohol increases a person’s sensation of warmth and draws blood away from vital organs. It also impairs judgment and can cause you to underestimate the extra strain on your body.

Don’t shovel immediately after a meal. Adding vigorous activity while digesting a meal can increase the strain on the heart.

Warm up first. Do some light exercises to warm up your muscles and increase your circulation. A warmup can also reduce the risk of muscle strain or pulled back.

Take off layers off as you go. Overheating will increase your blood pressure further, so strip down to just a sweater if needed.

Take lots of water breaks, just as you would during any other exercise.

If you’re feeling tired or dizzy, stop. Go inside and plan to finish the job later. If you are still feeling unwell even after stopping, call 911.

Snow blowing is also hard work. Snow blowers still have to be pushed through the snow, which can be strenuous depending on how wet the snow is.

Ask for help from family or neighbours. If you know a storm is on the way, start making calls ahead of time.

Use your community's snow removal service: Many communities will clear the sidewalks outside the homes of older or disabled adults or those with heart conditions if you call and make the request.

Learn CPR. Effective hands-only CPR from a bystander can double or triple a heart attack victim’s chance of survival.