A wildfire smoke advisory has been issued for portions of Central and Northern B.C. by the Environment Ministry and Environment Canada.

The advisory applies to Prince George, Vanderhoof, Quesnel, Williams Lake, Mackenzie, the B.C Peace River and Fort Nelson areas. Smoke concentrations will vary widely as winds and fire behaviour change.

Environment Canada advises residents to avoid strenuous outdoor activities.

"If you are experiencing any of the following symptoms, contact your health care provider: difficulty in breathing, chest pain or discomfort, and sudden onset of cough or irritation of airways," said the warning.

"Exposure is particularly a concern for infants, the elderly and those who have underlying medical conditions such as diabetes, and lung or heart disease."

There are currently about 84 active wildfire larger than 10 hectares burning in B.C., according to the B.C. Wildfire Management Branch.