Officials are warning of poor air quality in parts of Maine and New Hampshire.
The National Weather Service issued a heat advisory and an air quality alert with temperatures projected to climb to 90 degrees with high humidity on Monday in southern Maine.
The air quality alert affects coastal Maine from Kittery to Acadia National Park, and is due to expire late Monday.
The weather service recommends that people limit prolonged or heavy outdoor exertion by taking breaks, seeking shade and keeping hydrated.
The New Hampshire Department of Environmental Services, meanwhile, has issued an air quality action day in parts of Rockingham and Hillsborough counties.