The Haliburton-Kawartha-Pine Ridge District Health Unit is sending out an extended heat warning for the area.

Emergency Preparedness Coordinator Carol Chan is encouraging residents to drink plenty of water, and seek out cool places.

Chan says to avoid heavy meals, and going out in the sun.

She says high temperatures can cause heat-related illnesses, like heatstroke, dehydration and exhaustion.

According to Environment Canada, a hot and humid airmass is on its way from the Gulf of Mexico and will stay until Thursday.

The heat will arrive this afternoon, with highs of 30 to 33 degrees.

Officials say nights will be warm and muggy with overnight lows of 20 to 23 degrees.