Provincial health officials are warning residents to cover up and wear mosquito repellent as the risk of contracting the West Nile virus grows this August long weekend.

Culex tarsalis, the type of mosquito that carries the virus, is most active and present in higher numbers around late July and August, according to the Ministry of Health. The risk of contracting West Nile is highest during this peak period.

“Protect yourself from mosquito bites by covering up and wearing repellents or reducing the amount of time spent outdoors,” said Phill Curry, the ministry’s West Nile Virus Coordinator. “Mosquitoes can be active at any time but are most active in the evening and throughout the night.”

The vast majority of people infected with West Nile experience no symptoms. Some become mildly ill, exhibiting fever, headaches and body aches.

A small number of people develop a more serious illness, called West Nile virus neuroinvasive disease, which includes inflammation of the brain. Recovery can take several weeks or months, according to the province, and some effects can be permanent.

Health officials asked residents to minimize their exposure to mosquitoes by eliminating the insects’ habitats in their yard.

Residents should clear their yards of items that collect water, regularly clean bird baths and eaves troughs, cover rain barrels with mosquito screens, and keep shrubs and lawns clear of overgrowth and debris, the province said.

West Nile symptoms usually occur two to 15 days after a person is bitten.