Purchase a heater with a guard around the heating element. A wire grill or other protection is essential to keep fingers or fabrics from touching the hot element. Portable electric heaters that heat by circulating oil or water, however, usually have lower surface temperatures and may not need guards.
If you have pets, consider replacing the carpeting before putting your home on the market. Many people are allergic to pets and extremely sensitive to pet odors, which even a recent, thorough cleaning may not mask. And worn carpeting, even if it is clean, can detract from a home’s overall appearance, giving the impression it has not been well maintained.