In the last episode of Season 1, the kids are running through the school hallways-- they are confronted by Connie Frasier and a bunch of agents, who El then kills. El collapses, weakened by her use of powers.
A few minutes later, the kids run into Mr. Clark's science classroom - Dustin is carrying the weakened Eleven and puts her on a table.....
BUT in the original script, Mike was supposed to be the one carrying Eleven.
The problem was that Finn Wolfhard could not carry Millie Bobby Brown. So, they improvised, changed the script and had Dustin (Gaten Matarazzo) carrying her instead.