Officials have issued yet another air quality advisory for Metro Vancouver and the Fraser Valley as smoke from wildfires burning in the B.C. Interior and western United States blows towards the coast.

“I would certainly expect... for the smoke to continue to build (and) elevated levels of particulate matter,” Geoff Doerksen, an air quality planner with Metro Vancouver, said Monday.

This is the fourth air quality advisory in the region this summer over what officials are calling the province’s most destructive and costliest wildfire season on record.

Metro Vancouver already experienced its longest-ever air quality alert in July and August. On Tuesday, Aug. 29, officials issued another air quality advisory, which they cancelled less than 24 hours later, only to issue a new one Monday morning.

Dangerously small particles associated with the wildfire smoke, known as PM 2.5 particles, “can be inhaled deep into your lungs, and go into your blood stream,” Doerksen said.

Children, the elderly and those with existing medical conditions are urged to avoid strenuous activity, particularly during the mid-afternoon and early evening, when ozone levels are at their highest.

Anyone who experiences symptoms such as chest discomfort, shortness of breath, coughing or wheezing should see their health care provider.

Officials say the advisory will likely stay in place until there is a significant change in weather.

Crews are currently battling a total of 162 wildfires across the province.

Since April 1, more than 1,200 wildfires have scorched a total of 11,461 square kilometres of land.

The advisory comes amid a heat wave that gripped much of the Lower Mainland over the Labour Day weekend.

On Friday, Environment Canada issued a special weather statement citing a “strong ridge of high pressure that's building over British Columbia.”

Saturday and Sunday saw daily highs in the 30s across most of the region.

On Monday, temperatures are expected to peak around the 27 C mark in Vancouver, but could feel more like the low 30s with humidex.

Abbotsford set a new Labour Day temperature record, reaching 30.7 C at around 12 p.m.

The daily temperature record also fell in Pitt Meadows, which reached just above 33 C.

The unseasonably warm weather is expected to persist until at least Thursday night, when possible showers could lead to cooler conditions.

With files from CTV Vancouver’s Sarah MacDonald