I have a multi-user ASP.NET app running against SQL Server and want to have StoredProcA create a #temptable temp table - not a table variable - to insert some data, then bra
Temp tables get created with name mangling under the hood so there shouldn't be conflicts between different stored procedure calls.
If you need to manipulate the same temp data in subsequent stored procedure calls, it's best to just go with a real table and use some sort of unique identifier to make sure you are only dealing with relevant data. If the data is only valuable temporarily, manually delete it once you're done.