Crews responded to the 300 block of Horsham Road around 6:30 Tuesday night.
Officials say construction workers were using gas and propane while working in a vacant storefront and it lead to a carbon monoxide leak.
The carbon monoxide was detected at the nearby Starbucks and multiple people complained of feeling sick.
Four people, two Starbucks employees and two customers, were taken to Abington Hospital for minor injuries.
Five other people were treated at the scene but refused hospitalization.
The incident remains under investigation.