This book is one of four books in the Science-by-Design Series created by TERC and funded by the National Science Foundation (NSF). It offers high school students a challenging, hands-on opportunity to compare the function and design of many types of handwear from a hockey mitt to a surgical glove, and design and test a glove to their own specifications. Students learn the basic principles of product design while exploring the principles of physics and technology necessary to construct and test an insulated glove. The activities have assessment suggestions and Internet extensions through the National Science Teachers Association's (NSTA) sciLINKS program and are designed to meet the new International Technology Education Standards as well as the National Science Education Standards. Key ideas include: (1) "Homeothermic process [maintaining a constant internal body temperature]"--the measured and perceived warmth of a hand is related to its direct connection to the body's heat engine and the hand's relatively large ratio of surface area to volume. Variables that add complexity to an insulated-glove system design relate to the multiple functions of the hand: an appendage for body cooling, environmental sensing, and manipulating objects; (2)"Heat energy transfer processes, insulation materials, and dexterity"--student teams measure temperature change over time as a gloved hand is exposed to cold. Properties of various materials are explored for their effect on hand warmth and dexterity; (3) "Inquiry"--experiments are designed by students to supplement "fair test" comparisons of several manufactured gloves. Students conduct "hands-in" research to determine combinations of glove materials that balance thermal effectiveness with dexterity for a specific function; and (4) "Design"--students undertake an iterative, multi-disciplinary process that includes research, testing, and evaluation feedback loops as part of the product development cycle. Students work in development teams to design and construct an insulated glove system prototype and present their research and development efforts in a product prospectus. Appendices contain inquiry and design processes, text reconstruction, and various factors and variables to consider during construction. (Contains a glossary and 28 references.) (CCM)