Police need the public's help to find an elderly Burlington woman with Alzheimer's who hasn't been seen since Tuesday.

Halton Police say Helen Robertson, 79, is known to walk long distances.

She was last seen at her Millcroft Park Drive home early Tuesday afternoon. Police say they're concerned about her, particularly with the hot temperatures.

"An extensive search was conducted overnight and will continue today with the assistance of our SIRT," police said in a statement, referring to the search incident response team.

Police want Burlington residents, particularly those living within the Millcroft area, to check their properties and buildings, as well as keep an eye out for Robertson.

She's described as white, 5'2" and 110 pounds, with white collar-length hair, a slim build and glasses. She's possibly wearing a red long-sleeved collared shirt and two different shoes.

Anyone with information should call Halton Police at 905-825-4747 ext. 2305.