Physics: Principles and Problems


Physics: Principles and Problems Glencoe Online
Science Home Product Info Site Map Search Contact Us  

In the News

A Really Hot Jacket
Posted March 2002

Clothing designed to keep people warm usually relies on the basic principles of insulation to do its job. Winter coats use different linings and fillings to trap the heat generated by the human body.

A new product is on the market that revolutionizes winter clothing by using a portable heat source to keep the body warm. High-tech jackets have been designed with heating coils in their fabric, powered by lithium-ion batteries. The earliest versions of these jackets can heat the wearer up to 114 degrees Farenheit.

The basic principle isnít all that different from an electric blanket or a heating pad. However, what makes this new product different is the type of material used to transmit the heat. Electric blankets have thick heating coils inside that can be bulky and make it impossible to wash without damaging the equipment.

This new technology uses stainless steel microfibers, which are thinner than a strand of human hair. Because they are made of stainless steel, these microfibers are flexible and washable, and they are seamlessly woven into the fabric itself. The microfibers are concentrated around the heart to keep the core of the body warm, and allow blood to carry the heat to the rest of the body.

Malden Mills in Lawrence, Massachusetts, developed this technology and is now using it to produce the Polartec fleece. They are also licensing the technology out to The North Face to make a jacket and Landís End to make a blanket.

In order to test the effectiveness of the jacket, The North Face buried a mountain climber in ice and kept him there until he started shivering and then had him turn on his heater. Within minutes, he stopped shivering.

Of course, such technology does not come cheap. Right now, the Landís End jacket costs $500 apiece. However, if you spend a lot of time outside in the cold, price doesnít seem to matter. Police, construction workers, and athletes from the Winter Olympics have all sought these special jackets. Likewise, the United States military is spending $17 million to buy Polartec fleeces.

Eventually, researchers believe they can use this microfiber technology for more than just a heating device for someone who feels cold. This stainless steel could possibly be used to transmit data and eventually integrated into a ďwearable computer.Ē Also, by infusing electronics into the very fabric of clothes, technology can be developed to monitor heart rates and vital statistics of a person.

Use the Internet to research insulation technology in winter clothes. Design your own experiment that tests the effectiveness of different insulation materials.


The McGraw-Hill Companies
Physics: Principles and Problems