(Portland, OR) -- A heat mapping study is underway in Portland. Volunteer drivers in vehicles equipped with special temperature sensors will drive designated routes three times a day. The temperatures will be recorded along those routes in Multnomah, Washington, and Clackamas counties. The goal is to determine areas that are hotter, so residents can take action to deal with the heat. The results of the study will be available at the end of the year. This is one of 17 data collection projects across the country to prepare communities for the increasing threat of extreme heat.