Nuheat. The company's pre-fabricated electric floor-warming mats come in 60 standard sizes and can be installed under tile, marble, and natural stone floors.

The product heats floors to about 84 to 88 degrees. The mats are 1/8-inch thick and will not affect the elevation of the room. (800) 778-9276. www.nuheat.com. Courtesy Nuheat Flextherm. The Flextherm floor-heating system uses heating cables and an electronic thermostat. The cables are 2-millimeters thick and are available in 120 volts and 240 volts. The thermostat features a ground fault circuit interrupter. (800) 353-9843. www.flextherm.com.

EasyHeat. Warm Tiles electric floor warming systems come in pre-terminated lengths with factory-sealed connections and can be used for 120- and 240-volt applications. The system can be installed directly onto plywood, concrete, or backerboard subfloors. (800) 523-7636. www.warmtiles.com.

Consolidated Plumbing Industries. Designed for fast, efficient installation, the Basic Radiant in-floor hot water radiant heating kit includes Dura-PEX tubing and a pre-engineered, ready-to-install control panel. The system requires only an attachment to a boiler or hot water heater, the firm says. (865) 690-1558. www.durapex.com.

Courtesy Warmly Yours Warmly Yours. The company's radiant floor heating system comes in mesh-backed mats or rolls that can be trimmed and turned to fit the space. The system is controlled by a basic digital thermostat or by an advanced model that allows users to program settings for morning, evening, and weekend hours. (800) 875-5285. www.warmlyyours.com.

Courtesy Watts Radiant Watts Radiant. UL-listed HeatWeave UnderFloor electric radiant heat mats can be installed easily between 16-inch joist spaces. A foil-faced insulation fills joist space to improve heat transfer. The mats are available in a range of lengths. (800) 276-2419. www.wattsradiant.com.