These are insulated cool boxes or bags that you keep cool with ice blocks or frozen drinks bottles.  These are the cheapest cooling solutions,  although there are some big beasts that can be quite pricey.  The advantage is that you don’t need a power supply and they can be used anywhere. They are ideal for day trips or overnight trips. If you are going away on a multi-day adventure, then you will have to keep refreezing your ice blocks. Some campsites have freezers available for this purpose.  To use it as effectively as possible, minimise the number of times you open the box.

These are also known as thermoelectric cool boxes. People often just refer to them as a 12v cooler box or car cooler. They are insulated boxes, that are powered by an electric fan. They are usually powered in your car by a 12v or you can get an adaptor and use it on the mains hook-up at a campsite. How cool it will keep your food will depend on the outside temperature. An average model may have a cooling power of 20 °C below the ambient temperature. These should be suitable for the UK climate, although it depends on what you want to keep in it. Ideally, raw meat needs to be kept under 5°C to avoid the growth of bacteria. The best temp for a fridge in your house is around 5°C. Some better performing electric cooler boxes might keep it 30 degrees below ambient temperature. A cheap electric cooler box is quite noisy and they usually drain the car battery fast if left charging without the engine off.