What the law requires
Regulation (EC) No 178/2002, Article 18 requires every food business to be able to identify the suppliers of its food and to give this information to the authorities on request. Regulation (EC) No 852/2004, Annex II, Chapter IX says a business must not accept raw materials that it knows or can reasonably expect to be contaminated, and that the cold chain must not be interrupted. In the UK, the Food Standards Agency pack Safer food, better business asks for the same kind of supplier records. The accepted temperatures and what you check at each delivery come from your own HACCP plan and the national guide.
Check the temperature, packaging, label and use-by date on delivery. Keep invoices and delivery notes so you can trace every product back to its supplier.