This post contains affiliate links. Learn more
Insulin degrades at temperatures above 25°C and loses effectiveness when frozen. For the 4.3 million people diagnosed with diabetes in the UK — particularly those on insulin — maintaining a safe storage temperature during travel, hot weather, or a power cut is not a comfort issue. It is a medical necessity. A warm day in a car, a camping trip, a heatwave with no air conditioning, a fridge that fails during a power cut: any of these scenarios creates a genuine insulin storage problem.
The Frio Insulin Cooling Wallet — often just called the Frio Cooling Wallet — requires no electricity and no ice. It works through evaporation — soak it in cold water for a few minutes, and it maintains a safe temperature of 18–26°C for 45 hours minimum, even in ambient temperatures of up to 37.8°C. Re-soak and it reactivates. Tested by the British Medication Devices Evaluation Unit and recommended by UK hospitals and clinics. At £15.95 and Amazon’s Choice with nearly 1,500 reviews, this is the go-to solution for a specific but important problem.
FRIO Insulin Cooling Wallet
Keeps insulin at safe temperature for 45 hours using only water — no electricity, no ice, no power required. Tested by the British Medication Devices Evaluation Unit and recommended by UK hospitals.
Current Price at time of writing: £15.95
Rated: 4.6/5 ⭐ from 1,547 reviews
How It Works
The wallet contains crystals that absorb water and form a gel matrix. When the wallet is soaked in cold water, the crystals expand and the evaporation of that water from the gel provides consistent cooling. This is not a new principle — evaporative cooling is one of the oldest thermodynamic tricks available — but the Frio wallet applies it specifically to the temperature range insulin requires.
The process:
- Submerge in cold water for 5–8 minutes until the crystals are fully expanded
- Remove and pat dry the outer surface
- Insert insulin (pens, cartridges, or vials depending on the size you purchase)
- The wallet remains at safe temperature for 45 hours minimum
- Re-soak and it reactivates — no charging, no consumables, no ice required
What This Review Covers — The Individual Size
The Individual size (reviewed here) fits one standard insulin pen or 2–3 insulin cartridges. It is the most portable option and the most commonly purchased. Frio make several sizes — if you need to carry a second pen, multiple vials, or need to fit larger insulin delivery devices, check the range before ordering. The listing explicitly notes this size will not fit an EpiPen — the Duo size is required for an EpiPen or a second pen.
Emergency Preparedness Angle
For the specific needs of insulin-dependent people during power cuts: if the fridge is off, insulin stored at room temperature in typical UK conditions (under 25°C) is safe for 28 days for most insulin types — check your specific insulin’s documentation. The Frio wallet becomes the critical item during a heatwave or warm summer power cut where room temperature exceeds 25°C. At that point, the wallet maintains safe temperature without any power source for as long as water is available to re-soak it.
For travel: taking insulin on a flight, to a hot climate, or camping removes access to consistent refrigeration. The Frio wallet covers those scenarios completely. In-use insulin is safe in the wallet for up to 28 days.
Limitations
The Frio will not keep insulin cold — it keeps it cool within the safe range. It cannot substitute for a fridge for insulin that should be refrigerated and has not yet been opened (unopened insulin stores in a fridge at 2–8°C). Once a pen is in use, the Frio covers the safe temperature requirement. For the specific scenario of a power cut where opened insulin needs protection, this wallet is the correct solution. For longer-term storage of sealed stock, a cooler bag with ice packs is required alongside this.
FRIO Insulin Cooling Wallet
Keeps insulin at safe temperature for 45 hours using only water — no electricity, no ice, no power required. Tested by the British Medication Devices Evaluation Unit and recommended by UK hospitals.
Current Price at time of writing: £15.95
Rated: 4.6/5 ⭐ from 1,547 reviews
What the Rest of the Team Think
🦆 Keith the Prepper
My wife has Type 2 diabetes and doesn’t use insulin, but I’ve bought her one of these anyway for the principle of the thing and because my sister-in-law visits in summer and she’s on insulin. I also bought a second one for the bug-out bag, which my wife says is redundant. She is probably correct. But it weighs almost nothing and it might matter one day. Five stars for the technology alone.
⭐⭐⭐⭐⭐
🪖 Black Panther
Field operatives with medical conditions require medical logistics planning. Insulin is a high-priority medication dependency — failure mode can be rapid and severe. The Frio eliminates power dependency from the cold chain for in-use insulin. No ice, no electricity, no maintenance beyond water. This is the correct solution for any operational context where a fridge is unavailable. Fully commend it.
⭐⭐⭐⭐⭐
🤡 Camping Clown
I have a battery-powered insulin cooling case with two temperature alarms and Bluetooth connectivity that I bought when I was testing cold chain solutions for my camping medical kit. I don’t actually use insulin. This Frio wallet, which does not require batteries, does not require Bluetooth, and costs £15.95, is objectively a better solution for most people. I’m keeping my one as a backup, obviously.
⭐⭐⭐⭐⭐
🐾 Weekend Warrior
Not a product I personally need but I bought one for a friend who’s on insulin and goes camping. She says it’s transformed her planning — she used to carry ice packs in a cooler bag which melted and needed replacing. The Frio just needs water, which is available everywhere. Brilliant concept and brilliant execution. Four stars only because I can’t personally give a performance review.
⭐⭐⭐⭐
🐕 Pickle
“Snorgle!”
(Translation: “Dad soaked this in water and said it was for medicine. I tried to investigate and was redirected. I think it smells fine. Important medicine must stay cool. I understand this. Snorgle.”)
🐔 Chicken Licken
No batteries. No electricity. Works on basic chemistry. The fact that this isn’t in every diabetic person’s bag everywhere they go is the real mystery here. The pharmaceutical companies have an interest in you staying refrigeration-dependent, obviously. This removes that dependency entirely using water and crystal technology. Five stars. Buy several.
⭐⭐⭐⭐⭐
📋 Calm Clarissa
The power cut medical supplies checklist has a specific insulin section. For households with an insulin-dependent member: Frio wallet charged and ready, 28-day supply buffer checked quarterly, power cut protocol includes locating the wallet immediately and soaking within the first hour if the outage is likely to be extended. This product is non-negotiable in that scenario. Properly rated and properly recommended.
✅✅✅✅✅
💄 Survivl Gurl
I did a carousel post on festival prep for people with medical conditions and this got so many comments from people who’d never heard of it. The diabetic community on TikTok are all over it but the general prepper community hasn’t caught on yet. Super lightweight, fits in any bag, no batteries to remember. If you’re diabetic and you don’t have this, please look into it.
⭐⭐⭐⭐⭐
🌿 Aroura
This product works through the natural principle of evaporative cooling — the earth’s own method of temperature regulation, as seen in rivers, morning dew, and the cooling breath of the forest. No chemicals, no electricity, just water and intention. I find that deeply aligned with my values, and the universe clearly does too, because it works. Namaste 🙏
⭐⭐⭐⭐⭐
Frequently Asked Questions
Does this work for storing unopened insulin?
No. Unopened insulin requires refrigeration at 2–8°C. Once a pen is in use, most insulin types are safe at 18–25°C for up to 28 days. The Frio wallet is for in-use insulin only — not as a replacement for refrigerating sealed stock.
How often do I need to re-soak it?
The wallet provides minimum 45 hours of cooling per soak. In very hot conditions (above 30°C ambient), performance may be slightly reduced. Re-soak whenever the outer surface has dried out completely.
Can I put an EpiPen in this wallet?
No. The Individual size will not fit an EpiPen. Frio make a Duo size specifically for EpiPens or two standard insulin pens. Check the correct size before ordering.
Does it work in very hot climates?
Yes — tested to maintain safe temperature in sustained ambient temperatures of 37.8°C. The hotter and drier the environment, the faster the evaporation and the more effective the cooling. In humid conditions, evaporation slows slightly.
What should I do with insulin during a power cut?
If room temperature is under 25°C, in-use insulin is generally safe without the wallet for the duration of a typical UK outage. If temperatures are high (summer heatwave, south-facing rooms), soak the Frio wallet and transfer in-use insulin. Check your specific insulin’s documentation for its exact temperature tolerance.
Build Your Resilience
Further Reading: Related Guides
All our guides can be found listed on our resilience hub.
📡 Find Us Everywhere
Daily briefings, prep guides, and real-time updates across every platform. Pick yours.
Free. No commitment. Stay anonymous on WhatsApp & Telegram.
Stay Informed on UK Preparedness
Join our newsletter for UK-specific preparedness tips, product recommendations, and real-world advice for households.
Subscribe to Our Newsletter