Foil Emergency Survival Blankets (pack) review
By Tom Calder
For a couple of pounds these do exactly one job well: reflect back most of your body heat to fend off shock and hypothermia while you wait for help. Treat them as a sensible backstop, not a substitute for proper warm clothing or a real sleeping bag.
- Best for
- A near-free line item that belongs in every grab bag, car and first-aid kit.
as of 2 Nov 2026, 16:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.We earn a commission if you buy through the retailer links on this page. It doesn't change our verdict. How we make money →
Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Extremely cheap and light, so there's little reason not to stash one in every bag, car and kit
- Packs down smaller than a phone yet opens to a full adult 210 x 130cm, reflecting around 90% of body heat
- Also work as an emergency windbreak, rain sheet or ground signal, adding versatility for the price
Worth knowing
- Thin and prone to tearing; most are effectively single-use once unfolded and hard to refold
- Noisy, sweaty and offers little padding from cold ground on their own
ⓘ As an Amazon Associate, PreparedBritain earns from qualifying purchases. We may earn a commission when you buy, or a fee when you request a quote, through our links. When two products are close, commission can decide which one we pick. A clearly better product always wins. Amazon prices come from Amazon's own product data and show the date and time they were retrieved. Prices at other retailers are checked by us, less often. Prices and stock can change at any time, so always check the retailer's price before you buy.
Our review
A foil survival blanket is a sheet of aluminised polyester, usually about 130 by 210 cm, that folds to the size of a packet of tissues. It is the cheapest item in any first aid kit and St John Ambulance names it in its hypothermia advice. Keep several, but understand what it does: it stops heat radiating away and keeps wind and rain off, and it insulates very little on its own.
What it is
UK first aid suppliers such as Steroplast and Reliance Medical sell these as 130 by 210 cm sheets of aluminised polyester film around 12 microns thick, silver on both sides or silver and gold, weighing around 50 g each. The multipack we list is a generic pack of four. Makers claim they reflect anywhere from 80% to over 90% of body heat; treat those figures as marketing, since the film is a radiant barrier and the real benefit depends on how well it is wrapped and what is underneath.
They tear easily once opened, crackle loudly, trap sweat against the skin and almost never refold into their packet. Count them as single-use.
What the first aid advice says
St John Ambulance's hypothermia guidance tells you to lay the person on a thick layer of dry insulating material, and adds: "If available, wrap them in a foil survival blanket." The NHS says to remove wet clothing and wrap the person in a blanket, sleeping bag or dry towel, making sure the head is covered. The order matters: insulation underneath, dry layers, head covered, then the foil on the outside to stop radiant loss and block wind.
A 2022 review of survival blankets in the journal Wilderness and Environmental Medicine concluded that in cold, windy conditions a foil blanket "probably best serves as a waterproof outer covering". That is the honest summary. On its own, on cold ground, it will not keep someone warm overnight; over a sleeping bag or a wool blanket, it adds a windproof, waterproof shell for a few grams. Our first aid kit checklist puts one in every kit for that reason.
How it compares
If you want something to actually sleep in, the Blizzard survival bag is a three-layer reflective bag that traps air, and the SOL Escape bivvy is breathable enough to use for a night without soaking the inside. Both cost many times more than a foil sheet and both earn it. The Lifesystems survival shelter is the group option for a car or a walking party. On the first aid page the foil pack is the item you add to every kit, bag and glovebox because there is no reason not to.
Our verdict
Buy a multipack and put one in the car, one in each grab bag and one in the first aid kit. Skip the idea that they replace a sleeping bag, a wool blanket or warm clothing for a planned night out: they are the outer layer in an emergency, not the insulation. Check the packets every year or two, since the film becomes brittle with age.
A researched review, built from the maker's specs, manual and UK listings; facts checked 2 Nov 2026. Sources: St John Ambulance: hypothermia first aid; NHS: hypothermia; Wilderness and Environmental Medicine: review of survival blankets (PubMed); Steroplast: foil blanket specification.
Who shouldn't buy this
Don't rely on one as your main cold-weather layer for planned hikes or camping in exposed conditions. For that, spend more on a reusable Blizzard-style bag or a proper bivvy; the foil sheet is a get-you-through-an-emergency item, not a comfortable overnight solution.
Key specs
| Type | Aluminised Mylar foil (silver, both sides) |
| Pieces | 4 |
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the UK price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for Households wanting a fit-and-forget CO alarm to sit near any fuel-burning appliance.
as of 2 Nov 2026, 16:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Best for Reliable everyday protection on landings, hallways and living rooms.
as of 2 Nov 2026, 16:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.
Best for A family home or caravan that wants plenty of plasters, bandages and two ice packs in one fold-up bag.
as of 2 Nov 2026, 16:07 GMT · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.co.uk at the time of purchase will apply to the purchase of this product.Questions
How do you use a foil blanket on someone with hypothermia?
Follow St John Ambulance: get them somewhere sheltered, lay them on a thick dry insulating layer, replace wet clothing, cover the head, then wrap the foil blanket around the outside. Call 999 if they are confused, drowsy or not improving.
Will a foil blanket keep me warm overnight in a car?
Not on its own. It blocks wind and radiant heat loss but has almost no insulation, so use it over a coat, a sleeping bag or a wool blanket, and keep the car's own insulation in mind: sit on something, not the cold seat.
Are they reusable?
In practice no. The film tears once unfolded and rarely refolds, so treat each as single-use and keep several.
What size are they?
Most UK first aid suppliers sell them at about 130 by 210 cm, enough to wrap an adult. Check the pack, as some bargain multipacks are smaller.
Free alerts for your home
Home Alerts emails you when a power cut, a Met Office warning or a flood warning covers your postcode. Free for your own home. Sign up in a minute.
Start free →