Phase-change materials keep astronauts warm in the black void of space and cool in the solar glare. Microencapsulation is the bane of scent-sensitive magazine readers. Now two companies-Outlast Technologies, based in Boulder, Colo., and Frisby Technologies, based in Freeport, N.Y.-have married these technologies to create new kinds of clothing that regulate the wearer's body heat.

Select from the choices above to read the entire article.