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B.C. workers warned to look out for heat injuries as temperatures soar

WorkSafeBC puts out a warning as an incoming heat wave expected to bring peak temperatures to 40 C in some parts of the province this week.
pemberton farmer
A farmer and son inspect their organic family farm in Pemberton.

B.C.’s workers' compensation board is warning employers and staff to be on the lookout for heat stress as the province plunges into another heat wave. 

By Monday morning, Environment Canada issued heat warnings in 33 regions across British Columbia — stretching from Vancouver Island to the Alberta border and as far north as Kitimat. 

In B.C.’s Lower Mainland, temperatures are expected to peak from Wednesday to Friday this week with daytime highs of up to 35 degrees Celsius; in the Okanagan Valley, daytime highs are projected to climb as high as 40 C.

“We are hoping that the serious heat wave in 2021 has raised awareness about the dangers of working in high temperatures,” said WorkSafeBC’s senior manager of prevention field services Suzana Prpic in a written statement. 

“Whether you are working outdoors on a farm or construction site, or indoors in a restaurant kitchen, or a factory floor, heat stress can cause serious injuries and even death.”

Over the course of a week in late June and early July 2021, dozens of temperature records fell across B.C. as a heat dome scorched the region. In Lytton, B.C., an all-time Canadian temperature record was broken as the heat climbed to nearly 50 C. 

An estimated 619 people are now thought to have died from the heat — provoking a widespread review of how government and emergency services can better prepare for rising temperatures. 

Under a new BC Heat Alert and Response System (HARS), a provincial group of experts will assess weather projections across multiple regions of the province, issuing warnings through a two-tiered heat alert system.

The new system starts with a heat warning that will indicate temperatures are rising and are expected to exceed regional thresholds for minimum daytime and nighttime temperatures. 

Across B.C., the regional temperature thresholds are:

  • Lower Mainland, Vancouver Island: daytime high of 29 C, nighttime low of 16 C
  • Fraser Valley: daytime high of 33 C, nighttime low of 17 C
  • Southeast (including the southern Okanagan): daytime high of 35 C, nighttime low of 18 C
  • Northeast: daytime high of 29 C, nighttime low of 14 C
  • Northwest: daytime high of 28 C, nighttime low of 13 

Once those temperature thresholds are met and are expected to increase over a three-day period, the government will send out an emergency broadcast alert through the national text alert readiness system, radio and television. That's different from flood or wildfire warnings, which are currently issued at the municipal or regional level.

Meanwhile, cities across the region are sending out their own warnings and offering resources to help people stay cool.

Monday morning, the City of Vancouver issued a municipal heat alert calling on friends, family members and neighbours to check in on people over 60 years old, who live alone, have preexisting health conditions, have difficulty moving, or are marginally housed.

Extreme heat can also be deadly for young, healthy adults, and in certain jobs, just going to work puts them at risk. 

According to WorkSafeBC, there were 115 worker claims related to last year’s heat wave, a 180 per cent increase from the previous three-year average of 41 claims. 

Of those, more than one-third of the heat-stress claims are for indoor workers. 

WorkSafeBC requires employers to carry out heat stress assessments, and where appropriate, put in place a heat stress mitigation plant to train people on recognizing the symptoms of heat-related injuries. 

How heat kills

Death by heat starts slow. Too much time under the sun or stuck in a hot apartment has made you tired, and at times, dizzy. 

If you are an outdoor worker — a firefighter, a baker, a farmer or a construction worker — you face bigger risks when heat waves hit. Genetics matter less than age and the ability to get out of a wheelchair or bed, Dr. Tom Kosatsky, the BC Centre for Disease Control’s former medical director of environmental health, explained.

Those over 65, who are overweight or have pre-existing medical conditions, like heart disease or high blood pressure, tend to have a harder time avoiding the worst heat illnesses, he said.

Medication, such as diuretics, or recreational drugs like cocaine and amphetamines can interfere with your body’s ability to compensate for the heat. Alcohol only accelerates dehydration. Alone under punishing heat and with little water, those factors set the stage for a devastating spiral. 

Heat stress

As you begin the march toward hyperthermia, you might have a headache, feel tired or dizzy.

When heat stress hits you, you know you’re thirsty. You need water.

Heat fatigue

Your palms sweat. You don’t want to do anything. 

You got too much sun — a heat rash has flared up in your armpits and elbow creases.

Or maybe you forgot to put on sunscreen at the beach. You are burned. 

But it’s nothing you haven’t dealt with before.

Heat cramps

The mercury rises, your dehydration deepens. Painful muscle spasms come and go due to a lack of electrolytes.

All that sweating has depleted your body of vital minerals like potassium, sodium and calcium — Gatorade, basically — that help fire the chemical reactions in your muscles. 

Anyone working hard in hot conditions is especially vulnerable, and heat cramps are known to hit hikers and people working under the sun.

“It can occur anytime you’re dehydrated,” said Kosatsky. “But it’s much more likely to occur in the heat.” 

At this point, finding a cool place and restoring fluid with electrolytes can bring a person back. But if you’re stuck in an apartment or caught under the sun, things can turn quickly.

“People can go one way or another,” said Kosatsky.

Heat syncope

The other way? Heat syncope. 

You speak in broken words, unable to string together full thoughts.

A lack of water has reduced the volume of blood in your body. As the blood thickens, your body fights to keep your temperature down by pushing blood to the skin to induce sweating. 

An adult can lose a litre of water an hour this way; if they don’t drink more, the blood continues to thicken in a vicious cycle, drawing blood from the brain and sending your head spinning in dizziness. 

You faint.

Heat exhaustion 

Your heart, your body’s biological pump, is pounding to drive blood toward the skin — to sweat. 

You have a fever. You’re irritable. Sweat pours out of your body as it works to stay in the range where human life is possible. Dizziness has escalated to disorientation. You are confused, can’t see straight and want to vomit.

You need cold compresses, an ice-cold shower or a jump in the lake to regulate your body temperature. You need water.

“Paradoxically, they deny thirst, they get so far along they don’t feel thirsty anymore,” said Kosatsky.

Heat stroke

Your sweat runs dry, spiking your fever to over 41 C.

Your body wants to move into damage control, it wants to move blood to the organs keeping you alive. But without enough of it to go around, your blood pressure plummets, the vital fluid now a thick sludge. 

As blood retreats from your organs, blood vessels begin to collapse. 

You start to hallucinate. 

Then your organs shut down — maybe the kidneys first. 

The mud-thick blood now clogs in your blood vessels, perhaps triggering a stroke.

Your heart fails.

“That’s lethal,” said Kosatsky.

Start with prevention

The best way to prevent heat-illness is to start planning early, according to WorkSafeBC.

Employers are encouraged to: 

  • Monitor temperatures and require that workers are not working alone. 
  • Make sure first aid training and emergency planning are up to date 
  • Make sure employees have enough time to rest. As WorkSafeBC puts it, “when a worker feels ill it may be too late.”
  • Rotating activities at work or using more workers can offer employees time away from the hottest jobs
  • Make sure there are cooling areas on site that provide shade and water
  • Exposure can also be reduced by making “physical modifications to facilities, equipment, processes.”

Workers, meanwhile, can protect themselves by drinking at least one glass of water every 20 minutes; wearing light-coloured, loose-fitting clothing that can breathe; and taking breaks in a cool-ventilated area. 

Other ways to prevent heat stress at work include: 

  • Doing the hardest work in the coolest parts of the day (avoid 11 a.m. to 3 p.m.)
  • Consider any medications you are on or pre-esixting health conditions that may make you more prone to heat illness.
  • Monitor for the signs and symptoms of heat stress in yourself and your co-workers.