Steroplast Emergency Foil Blanket: What It Does and How to Use It

A foil blanket is a thin sheet of plastic with a shiny metal layer that reflects body heat back towards the person wearing it. The Steroplast Emergency Foil Blanket is 130cm by 210cm, made from 12µm PET film with aluminium, and the maker says it reflects up to 90% of body heat while keeping out wind and rain¹. It folds into a sealed bag about 7.5cm by 11.5cm, so it fits in a coat pocket, a glovebox or a first aid kit¹.

You use it by unfolding it completely and draping it around someone from the shoulders down to their feet, shiny side towards the body, so the reflective layer holds their warmth in¹. It is designed for the prevention and treatment of hypothermia, and for evacuations, first aid and rescue¹. It is a single-use item: once opened and used, replace it¹.

It is not a substitute for medical help. If someone is shivering uncontrollably, numb, confused or drowsy after cold exposure, or has any sign of injury, seek medical assistance promptly, because those can indicate hypothermia or shock¹. The sections below cover what the blanket is for, how to wrap someone in it, how to use it on a child, when foil is not enough, and how to store it so it is there when you need it.

What the Steroplast Emergency Foil Blanket is for

The maker describes the blanket as specifically designed for the prevention and treatment of hypothermia, and for emergency evacuations, first aid and rescue scenarios¹. In plain terms, it is the item you reach for when someone is cold, wet or shocked and you need to stop them losing heat fast. The NHS lists an aluminium blanket among the things to keep in a first aid kit, because it retains body heat in emergencies, which it calls essential for first aid and survival³.

That makes it a natural fit for several places in a household's kit. The Met Office's winter driving checklist suggests a foil or emergency blanket with 90% heat reflectivity or higher⁴, and the Scottish Government's emergency kit guidance includes a blanket in the car kit⁵. At home, official grab bag lists include blankets among the essentials⁶, and flood guidance suggests packing blankets alongside warm clothing, waterproofs and a first aid kit⁸.

What the blanket does not do is generate heat. It reflects what the body is already producing and blocks wind and rain, which is why it works best on someone who is dry or being dried, and wrapped closely. It is also not a shelter, a stretcher or a substitute for getting someone out of the cold. Think of it as the layer that buys time while you do the rest.

The 25 pack suits a household that wants blankets in several places at once: one in each grab bag, one in the car, one in the first aid kit, one at work. Both are the same product in different quantities.

Size and material: 130cm by 210cm of 12µm PET and aluminium

The Steroplast blanket is cut to 130cm by 210cm, with a tolerance of 1mm on each dimension, and made from PET film (polyethylene terephthalate) with an aluminium layer¹. The film is 12µm thick¹. That is thin enough to fold into a pocket but strong enough to be handled: the maker gives a tensile strength of at least 210MPa in both directions and an elongation at break of at least 80%¹.

The maker's own instructions describe the blanket as 1.4m by 2m when opened fully, which is a rounded version of the 130cm by 210cm cutting size¹. The 10 pack is listed by the maker as 140cm by 210cm unfolded². Where the maker's figures differ slightly between pack sizes, treat the cutting size on the 25 pack page as the specification and the other as a rounded description.

Reflects up to 90% of body heat and keeps out wind and rain

The maker says the blanket is specifically designed to reflect up to 90% of body heat, and that its waterproof and windproof capabilities provide protection from the elements¹. The 10 pack page puts it more simply: it protects the user from the wind and helps retain some of their body heat, which is useful for treating or preventing hypothermia in an emergency².

Those two jobs matter in different conditions. In wind, the blanket's outer layer stops moving air stripping warmth from the skin. In rain, it keeps clothing dry so it can keep insulating. In cold but still conditions, the reflective layer does most of the work by bouncing radiated heat back towards the body. The Met Office's winter driving checklist treats 90% heat reflectivity as the benchmark to look for⁴, which is the figure Steroplast quotes for this blanket¹.

The blanket is not a heat source and does not warm someone who is already deeply cold on its own. Official first aid guidance for hypothermia is to cover the person with dry blankets or clothing to minimise heat loss⁹, and the NHS advises wrapping yourself in something warm like a blanket, sleeping bag or dry towel if you have frostbite¹⁰. A foil blanket does that job when nothing else is to hand, and it does it in a package small enough to carry.

How to wrap someone in a foil blanket

The maker's instruction is to unfold the blanket completely to maximise its size and drape it around the individual from the shoulders down to their feet¹. Work in that order: open it fully first, because a half-opened blanket covers less and tears more easily, then place it over the shoulders and let it hang to the feet.

1. Move the person out of the wind and rain if you can, and remove or wring out wet outer clothing.
2. Unfold the blanket completely¹.
3. Drape it around them from the shoulders down to their feet.
4. Keep the face clear and let them sit or lie down. If they are in shock, help them to lie down on a blanket or rug to protect them from the cold, and raise and support their legs above the level of their heart to improve blood supply to the vital organs¹¹.
5. Get medical help if they are not recovering, or if there are signs of hypothermia or injury¹.

A foil blanket is not the right cover for a burn. Official burn first aid is to cover the burn with cling film or a clean, non-fluffy dressing¹², and NHS guidance for children says to lay cling film over the burn rather than wrap it around, or use a clean plastic bag or something clean and non-fluffy like a cotton pillowcase or linen tea towel, to reduce the risk of infection¹³. The Red Cross adds that cling film or plastic will not stick to the burn and reduces pain by keeping air from the skin's surface¹⁴. Keep foil for warmth, not for wounds.

Using a foil blanket on a child safely

The maker states that the blanket is primarily designed for adults, but can be used for children with caution, ensuring it does not cover their faces or restrict their movement¹. That is the whole rule: it is a wrap, not a swaddle, and the child's face and arms should stay free.

In practice, that means draping it over the shoulders and letting it hang, rather than tucking it in tightly or wrapping it round a baby like a shawl. A child who is frightened or struggling will pull at it, and a thin film will tear. If a child is cold and wet, dry them first, then drape the blanket over dry clothing or a towel, and keep them close to an adult for warmth.

For a baby or small child who is unwell, the priority is getting them assessed rather than improvising with kit. The NHS advises that if a child has an accident, you should get medical help if you are worried¹³. The Child Accident Prevention Trust's advice on burns is not to cover the face when dressing a burn¹⁵, and the same principle applies to a foil blanket: never let it cover the face.

When foil is not enough: signs of hypothermia that need medical help

A foil blanket holds heat in, but it cannot reverse hypothermia on its own. The maker's safety warning is to seek medical assistance promptly if there is uncontrollable shivering, numbness, confusion or drowsiness after exposure to cold, or any signs of injury, as these can indicate hypothermia or shock¹. The NHS adds that typical signs of hypothermia include shivering, slow breathing, tiredness or confusion, and pale, cold skin¹⁶.

The Resuscitation Council's first aid guidelines describe the principle behind the blanket: insulation means covering the person with dry blankets or clothing to minimise heat loss⁹. A foil blanket is one way to do that when nothing dry is available, but if the person is not warming up, is getting drowsier, or has been in cold water or snow for a while, that is a call for help, not more foil.

Heat is the other direction. In hot weather, the NHS advises wrapping a person with heatstroke in a cool, wet sheet, or fanning them or sponging them with cold water while waiting for help¹⁷. A foil blanket is the wrong tool there: it reflects heat back, which is the opposite of what you want. Keep it for cold, wind and rain.

Storing the blanket in a grab bag or first aid kit

The blanket comes individually sealed in a pocket-sized poly bag¹, which is what makes it easy to store. Official grab bag guidance is consistent about where blankets belong: flood guidance suggests packing blankets with warm clothing, waterproofs, rubber gloves and a first aid kit⁸, and other official lists include blankets among grab bag essentials⁶. West Yorkshire Prepared's flooding checklist goes further and suggests foil blankets at one per household member¹⁸.

The general rules for storing an emergency kit apply. Keep the kit together in a designated place that all household members know¹⁹, and keep it somewhere you can easily get to²⁰. A foil blanket is light and flat, so it can go in the grab bag, the car kit, the first aid kit and a coat pocket without adding bulk.

• Grab bag: foil blankets, 1 per household member¹⁸
• Car: one in the glovebox or boot kit, alongside a blanket as the Scottish Government advises⁵
• First aid kit: one alongside dressings and gloves³
• Home kit: blankets are on official home emergency kit lists²¹

Store it dry and out of direct sunlight, and check it when you check the rest of your kit. If the sealed bag is torn or damp, replace the blanket. For more on where to keep supplies and how to check them, see Checking and Restocking Supplies and Where and How to Store Your Supplies Safely.

Single use: why each blanket should be replaced after use

Steroplast states that the blanket is designed for single use to ensure effectiveness¹. That is not a marketing line: a foil blanket that has been opened, crumpled and wrapped around someone will not fold back as flat, may have picked up dirt or damp, and may have small tears that let wind through. A fresh sealed blanket is the one you can rely on.

The practical rule is to replace it as soon as you have used it, and to check the sealed bag when you check your kit. The same habit applies to other blankets in the home: guidance on electric blankets says to stop using the blanket immediately and replace it if you spot danger signs²², and to replace them every 10 years²³. Those rules are for electric blankets, not foil, but the habit is the same: inspect, replace, do not stretch a blanket past its job.

For a household, that means buying in a pack size that leaves you spares, so a used blanket can be replaced and one kept in each place. Note the date you put them in the kit and check them at the same time each year.

Where the blanket fits in a wider kit

A foil blanket is one item in a household kit, not the whole of it. The NHS first aid kit list includes plasters, bandages, dressings, gloves and a resuscitation mask³, and official grab bag lists add a battery radio, wind-up torch, spare clothes, toiletries, bottled water and tinned food⁶. The blanket's job is warmth, and it does that best alongside dry clothing, a torch and a way to call for help.

If you are building a kit from scratch, start with the Emergency Kit section and the Household Preparedness Checklist. For the car, see What to Keep in Your Car; for leaving home in a hurry, see Grab Bags. If you want to understand how foil blankets work more generally, see Foil Blankets: How They Keep You Warm, and for choosing between a foil blanket and a survival bag, see Survival Bag or Foil Blanket.

Steroplast is a UK maker of first aid and medical supplies, and its public access trauma kit work with Manchester City Council, CityCo and Steroplast Healthcare distributed 180 PAcT kits across venues in Manchester's hospitality and entertainment sectors, featured on BBC's The One Show in September 2024. You can read more on the Steroplast brand page.