Their dream vacation turned deadly.

A Denver family who won a chance to stay in a nearly $9-million estate east of Aspen died there over the weekend of carbon monoxide poisoning.

The bodies of Parker Lofgren, 39, his wife Caroline, 42, and their children, Owen, 10, and Sophie, 8, were found Friday in the nearly $9-million estate.

A second family, who also won a silent auction for the right to stay at 3,250-square-foot home during the Thanksgiving holiday weekend, found the bodies in beds in the home just before 5 p.m.

A team of technicians determined the house's hot water and snow melting systems malfunctioned. This caused the extreme levels of carbon monoxide in the house.

Here is what you need to protect your family, courtesy of the EPA:

    CO Poisoning Symptoms

Know the symptoms of CO poisoning. At moderate levels, you or your family can get severe headaches, become dizzy, mentally confused, nauseated, or faint. You can even die if these levels persist for a long time. Low levels can cause shortness of breath, mild nausea, and mild headaches, and may have longer term effects on your health. Since many of these symptoms are similar to those of the flu, food poisoning, or other illnesses, you may not think that CO poisoning could be the cause.

Play It Safe

If you experience symptoms that you think could be from CO poisoning:

	DO GET FRESH AIR IMMEDIATELY. Open doors and windows, turn off combustion appliances and leave the house.
	DO GO TO AN EMERGENCY ROOM and tell the physician you suspect CO poisoning. If CO poisoning has occurred, it can often be diagnosed by a blood test done soon after exposure.
	DO Be prepared to answer the following questions for the doctor:   Do your symptoms occur only in the house? Do they disappear or decrease when you leave home and reappear when you return? Is anyone else in your household complaining of similar symptoms? Did everyone's symptoms appear about the same time? Are you using any fuel-burning appliances in the home? Has anyone inspected your appliances lately? Are you certain they are working properly?

    Prevention is the Key to Avoiding Carbon Monoxide Poisoning

	DO have your fuel-burning appliances -- including oil and gas furnaces, gas water heaters, gas ranges and ovens, gas dryers, gas or kerosene space heaters, fireplaces, and wood stoves -- inspected by a trained professional at the beginning of every heating season. Make certain that the flues and chimneys are connected, in good condition, and not blocked.
	DO choose appliances that vent their fumes to the outside whenever possible, have them properly installed, and maintain them according to manufacturers' instructions.
	DO read and follow all of the instructions that accompany any fuel-burning device. If you cannot avoid using an unvented gas or kerosene space heater, carefully follow the cautions that come with the device. Use the proper fuel and keep doors to the rest of the house open. Crack a window to ensure enough air for ventilation and proper fuel-burning.
	DO call the Consumer Product Safety Commission (1-800-638-2772) at cpsc.gov for more information on how to reduce your risks from CO and other combustion gases and particles.

	DON'T idle the car in a garage -- even if the garage door to the outside is open. Fumes can build up very quickly in the garage and living area of your home.
	DON'T use a gas oven to heat your home, even for a short time.
	DON'T ever use a charcoal grill indoors -- even in a fireplace.
	DON'T sleep in any room with an unvented gas or kerosene space heater.
	DON'T use any gasoline-powered engines (mowers, weed trimmers, snow blowers, chain saws, small engines or generators) in enclosed spaces.
	DON'T ignore symptoms, particularly if more than one person is feeling them. You could lose consciousness and die if you do nothing.

This story serves as a tragic reminder for moms that we should all have a working carbon monoxide detector in our homes. This one from First Alert is $30, with free shipping.

Our hearts go out to the Lofgren family in this horrific time.