Secret Service Urges Donald Trump to Scrap Outdoor Rallies

The Secret Service is pleading with Donald Trump's campaign team to stop holding rallies outdoors in order to avoid any future danger from would-be assassins.

Sources familiar with the matter confirm the Secret Service has raised red flags about events like the one Trump held in Butler, PA -- and his team is taking the note, agreeing to keep things indoors for now.

We're told Trump’s team is now on the hunt for indoor venues like basketball arenas to pack in the crowds ... after previously favoring outdoor spots for their size and lower costs.

Rallies are still on the calendar ... but so far, none are scheduled for outdoor venues.

The Washington Post first reported the Secret Service request ... right after the agency's Director Kimberly Cheatle resigned her gig on the heels of Capitol Hill grilling her about botching Trump’s detail in PA, where Thomas Matthew Crooks took a shot at DT.

Cheatle’s answers on what went wrong that weekend were pretty vague, and the Secret Service has now given itself 60 days to get to the bottom of it.