The Newton-Wellesley Hospital Blood Draw Lab - Natick is open to Mass General Brigham patients with an open laboratory order from their Mass General Brigham provider. No appointment is necessary, walk-in appointments are available. Walk-in appointments are welcome Monday through Friday from 8:00 am to 4:15 pm. The blood lab is closed for lunch from 12:15 pm to 1:00 pm daily. Closed on all holidays. Children 3 years old and older may receive this service.