The school first opened last week as a warming center and a place for local residents to take hot showers and charge electronics.
As the power outages caused by Superstorm Sandy stretched beyond Thursday, and temperatures dropped, the school was opened on a 24-hour basis so residents without heat could have a warm place to sleep.
Today, "everyone is welcome for one last hot shower or to power up their devices," Fellin said Sunday.
She also issued a "heartfelt thank you" to the volunteers who helped staff the shelter on a 24-hour basis, including teachers, custodians and administrators.
"This could not have happened without the generosity by one and all. Thank you for caring," she added.
Saucon Valley schools were closed all last week due to the power outage, as were most other local school districts.
Anyone who plans to use the showers at the middle school should bring their own towels and toiletries.
During the week, the social hall was open as a heated retreat, a place to get hot drinks and a place to charge phones and other electronic devices.