To adjust a Frigidaire freezer that is not cooling well enough, find the adjustment knob and turn it to a colder setting. The knob may be located inside or outside the freezer compartment depending on the particular model.
Wait 24 hours and if the freezer is still not cooling properly, try the following steps. First, check the arrangement of items in the freezer. If it is overfilled, it may not be able to keep everything cold enough. Make sure that any vents are not blocked off and that there is adequate airflow within the freezer. If that doesn't help, check to see if any drain lines are clogged. Another troubleshooting step to try is defrosting the freezer. When done, turn it back to your preferred setting and place food inside.
If none of these things fixes the problem, consult a professional appliance repair service. Model-specific tips may be found in the owner's manual.