By Pat Loeb

PHILADELPHIA (CBS) — Danger from the storm didn’t end when the wind and rain died down.  Some injuries occur in the aftermath.

According to the Hospital of the University of Pennsylvania, at least a dozen people have been treated at HUP for carbon monoxide poisoning in the last few days — mostly as a result of exhaust from portable electric generators used indoors.

Eight people had cases so severe that they were treated in the emergency room’s hyperbaric chamber, which administers oxygen at higher-than-normal pressure.

Dr. Kevin Hardy says many patients didn’t even realize what was happening to them.

“People will initially start having relatively nonspecific symptoms like headache, nausea, vomiting, dizziness, lightheadedness, feeling off balance,” he tells KYW Newsradio.

Dr. Hardy warns that anything that burns gives off carbon monoxide. Generators should be outside and well away from the house. Any inside device must be properly vented.

And keep a CO detector nearby, he suggests, “which will catch rising levels very early and give you time to get out.”