Thermos Cool Box

[whistonian]

I have purchased a 32 ltr, cool box and 2 x 400 gram ice packs.How many ice packs do you think I will need to keep the food frozen for 2 and a half hours.

[Ratty2E]

If the food is packed tightly and any gaps filled with newspaper then it will act as it's own ice blocks but a few extra wouldn't hurt. How long it would stay frozen depends on the quality of the cool box and the ambient temp. I would expect it to stay frozen for at least 2 1\2 hours easily with a couple of ice blocks if it stays closed.

[whistonian]

Cheers Ratty.

[ethandron]

I have a couple of insulated picnic cool bags, not sure of the capacity but they're the size of shopping bags, I bought them from tesco.
I freeze a couple of two pinters of milk and use them as ice packs, and fill the bags to bursting with chilled stuff from the fridge. After four hours in the car the milk is still frozen solid. I don't use ice packs.

[carrust]

You could also buy some ice from the supermarket, open the bag and chuck it into the coolbox.