Optimize and monitor your fridge and freezer temperatures

A couple of years ago I gave myself food poisoning — I watched the Simpsons in bed for two days. This sounds great, but I was extremely ill and the Simpsons has gone downhill.

So, with the memory of stomach cramps and the yellow blur of disappointment still fresh in my mind, I write this practical betterment with the hope of never repeating that experience…

Every year 1 in 6 Americans get food poisoning1 — a decent chunk of that comes from home prepared meals.2

Some foodborne illnesses can be avoided by properly cooking food — but not all. While some bacteria like Stapholococcus Aerius will be killed in high temperatures, the toxins they leave behind on your food can still poison you.3

Four germs that create toxins that can survive cooking — in the style of the Simpsons.

To prevent getting sick from Staph and other bacteria, you need to prevent it from growing in the first place — which means storing it at a safe temperature — at or below 40°F / 4°C in the fridge and at or 0°F / -18°C in the freezer.4

If your fridge or freezer isn't cold enough you could be risking food poisoning — if it's too cold you could be wasting electricity and creating defrosting work for yourself. Optimizing the temperature is a win either way.

How to monitor fridge or freezer temperatures

Fridge-freezers are notorious for having terrible user interfaces — they even get called out by Don Norman in his book Design of Everyday Things.5 But there are now modern fridges that have accurate temperature settings. If your fridge is like this you can safely skip these instructions — otherwise keep reading.

Monitoring fridge temperature requires a fridge thermometer. Luckily for you I'm happy to provide a link to where you can buy a fridge thermometer that's certified to do temperatures correctly.

Once you've acquired your fridge thermometer follow these steps until your fridge is in the safe temperature zone (at or below 40°F / 4°C for fridges and 0°F / -18°C for freezers.)

  1. Open fridge
  2. Put thermometer in fridge
  3. Close fridge
  4. Wait for 5 hours
  5. Check the temperature. If it's in the safe zone you're all good. If not adjust the meaningless dial in the appropriate direction and go back to step 3.  Usually the higher numbers on the dial mean colder, but there's only one way to find out!


  1. 1

    fda.gov — What You Need to Know about Foodborne Illnesses

  2. 2

    cdc.gov – Surveillance for Foodborne Disease Outbreaks United States, 2017: Annual Report

  3. 3

    fda.gov — the bad bug book

  4. 4

    fda.gov – are you storing food safely?

  5. 5

    The Design of Everyday Things by Don Norman informs a lot of the thinking behind Practical Betterments. So I suggest you buy a copy of it using yet another affiliate link I shall supply here: Amazon – The design of Everyday Things