Deputies said the generator was found in the garage, which had been converted as an extension of the home.
As a safety precaution, those using a generator should also have carbon monoxide detectors in every room.
The couple was transported to a local hospital for treatment of carbon monoxide poisoning.
Three of the people inside were dead, officials said.
Another person, who was able to get out of the house, collapsed outside and died, deputies said.
Angela Merkel: Germany ready to play 'active role' in North Korea diplomacy
Europe and in particular Germany should be ready to contribute a very active part. Merkel told Putin she supported efforts of the U.N.
Carbon monoxide is an invisible, odorless, tasteless gas, and is highly poisonous. The generator was powering a refrigerator, a standalone freezer and two fans.
An Orange County Sheriff's deputy arrived at the home Tuesday after a 911 call, but was overwhelmed by the fumes inside the residence, according to a statement obtained by PEOPLE. "Generators need to be kept outside homes and garages and away from open doors and windows, vents, and air intakes", warned the police.
"It's something you never expect to see or to witness ... we just seen these folks outside a couple of days ago", said neighbor Jordan Garcia.
The first deputy inside the door was overcome by fumes.
The victims' names have not been released. Depending on the level of exposure, carbon monoxide may cause headache, nausea, lethargy (or fatigue), weakness, abdominal discomfort/pain, confusion, dizziness, visual disturbances including blurred vision, numbness and tingling, loss of muscle control or coordination, irritability, agitation, chest pain, shortness of breath, palpitations, seizures, loss of consciousness, and in severe cases, death. News 13's Ybeth Bruzual sat down with an Orlando firefighter to discuss what needs to be done to prevent more deaths as the area recovers from Hurricane Irma.
- Vikings QB Sam Bradford Named Offensive Player Of The Week
- G5 Sahel : Ibrahim Boubacar Keïta est à Ouagadougou
- Kenny Chesney's Island Home Torn Apart by Hurricane Irma
- HBO To Film Multiple Endings Of 'Game Of Thrones'
- Trump calls on Congress to accelerate Tax reform legislation
- Pinellas becomes the latest school district to delay reopening to Monday
- Hurricane Irma gives Florida a coast-to-coast pummeling
- Rijiju hits at critics of India's handling of Rohingya Muslim refugees
- Philippe Coutinho Ready To 'Give Everything' To Liverpool, Says Teammate Alberto Moreno
- The Lamborghini Urus SUV is almost here