Temp table manipulation in Stored Procedure

I am pretty inexperienced when it comes to sql, but I am an experienced engineer.

Want to create a stored procedure. Within that procedure I am going to create a temp table with certain attributes read in from 2 other permanent tables. After that, within the stored procedure, I want to read the resulting rows of the temp table one by one (one of the attributes will be a key that I will use to access yet another permanent table). I dont know how to do this.

select key1, att1 into #temp_table
from permTable1
where
key > xx
date > 999999

insert #temp_table
select key1, att1 from permTable1History
where
key > xx
date > 999999

....this is where I am stuck....how do I now read the contents of the #temp_table within the stored procedure one by one, to pull out that key attribute, to use to read from another permanent table?

thanks,
Bill

Here are some ideas, assuming I am understanding your needs right.

1. Use UNION instead of combining in a temp table. This can also be placed in a view any stored procedures can access. 2. Combine the stored procedures so this code is in the beginning of the code and then you process it without going into another stored procedure.

3. Instead of #temp_table use 2 "#"s, (##temp_table) so it's accessible from outside procedures (use with caution)
The procedure actually just makes and populates the table but doesn't return any values. The calling procedure will have to run the procedure to populate the temporary table like so: (let's assume the above stored procedure is called sproc_make_temp_table)