After a user is logged into his system and opens my progamm he can see data from a database depending on his WindowsUsername(I wrote a little stored procedure for that). 

This Data comes from a query with a temporary Table (#temp). My question is now, if many users use this programm, after opening it they would all try to build the #temp Table within the stored procedure. Is that even possible?? Because if i try to build a tempTable with the same name the server gives me an error. Do i have to give dynamic TempTable names maybe according to the user who is logged in??? Or is there another better option?
MS-SQL Server