The concept of this fridge “Sure Chill” is taken from frozen lakes. It can remain cool for 35 days which is enough time for life-saving drugs to reach children that live in remote locations.

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Vaccines actually help saving lives unlike Jenny McCarthy says. According to UNICEF, roughly 3 million children were saved in 2011 due to timely vaccination. However, 1.5 million children died as they were not vaccinated.


It is estimated that 20% of world’s children do not have access to medical facilities; such children are called “final fifth”. Reaching such children is the biggest problem for aid agencies. Majority of these children belong to the poor families living in rural areas of Southeast Asia and Africa. For saving more lives, the aid agencies have to improve their transportation and storage facilities at these locations.

Solution: Sure Chill

One of the biggest problems of these areas with no electricity is to keep vaccines cool. Gates Foundation introduced “super-thermos” that works effectively in hot weather. A complete new appliance called “Sure Chill” fridge does the same work but in a much better way. Whether the power goes out or there is no power, this fridge stays cold.


A Wales based small company used a basic law of physics to develop this technology. Water has the least volume at 4 degree Celsius (39 degree Fahrenheit) and remains down. As temperature rises, the water expands and moves upward. The Sure Chill fridge uses this mechanism to circulate cold water in the compartment that is located around central chamber. The central chamber stays at the required temperature.


A layer of ice is formed at the top of fridge when power is on. As the power goes out, the water gets warm and moves up. The ice on top cools this water and it moves down. This process keeps continuing till the ice runs out. For some models of Sure Chill, this process can last for 35 days.

The inventor

Ian Tansley is the inventor of Sure Chill. He studied frozen lakes and wondered how come the top was solid while there was swimming fish below. He worked on how to apply this idea to regulate temperature in a machine.


Since then the company made 1500 fridges for different organizations including UNICEF and Gates Foundation. UNICEF and Gates Foundation are sending 200 such fridges to Philippines soon.


According to Tansley, this invention has allowed health workers to vaccinate more people. Usually vaccines arrive once a month at a place, and limited numbers of people get vaccinated because not everyone shows up. However, if refrigeration is available there for a longer period of time then a lot more people can get vaccinated.

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There are two ways to continue the refrigeration of this fridge. Either ice arrives with the consignment of vaccines or temporary electricity is arranged. The Sure Chill fridges for the Filipino Project come with solar panels that charge the machine from sun light.