Is it possible for SQL statements to execute concurrently within a single session in SQL Server?

I have written a stored procedure which makes use of a temporary table. I know that in SQL Server, temporary tables are session-scoped. However, I have not been able to find definitive information on exactly what a session is capable of. In particular, if it is possible for this stored procedure to execute twice concurrently in a single session, a significantly higher isolation level is required for a transaction within that procedure due to the two executions now sharing a temporary table.