I'm with welshladywhois40, give him the horrible hospital food and take lovely things for yourself 
You could take pretty much any picnic food (quiche, cold meats, hummus, pasta or potato salad, eggs, sandwiches etc) for the first day as it will be fine in the cool bag.
Things that don't need refrigerating that will be safe (and nice) if they go above 5C:
Breakfast ideas:
Porridge pots
Cereal with UHT milk
Croissants, pain au chocolat
Fresh fruit
Freeze yoghurt, milk fruit or fruit juice in pots - they will help keep the cool bag cold and be ready to eat/drink the next day
Lunch and dinner:
Pot noodles with extras eg chilli, spring onion
Tuna and bean salad from tins or those long life mixed tuna fillings for sandwiches)
Cup a soups with really nice bread eg cheese rolls, olive focaccia etc
Take a small knife and mini chopping board to make salads from vegetables that will keep well out of a fridge if they are whole eg carrots, avocado, celery, tomatoes, cauliflower florets, little gem lettuce (ideally, stand them in a few cm of water in a glass), tinned potato salad, saucisson sec or pepperami, tinned tuna or salmon (if you are okay with the smell), cheeses that don't need to be kept cold (eg mature waxed cheddar, babybels, parmesan, pecorino romano), croutons, nuts, salad dressing that doesn't need to go in the fridge.