Hand warmers are safe products used as intended. The one real risk is the one people do not expect, so it is worth stating plainly.

What a low-temperature burn is

Skin can be damaged by prolonged contact with something only moderately warm — well below the temperature that makes you pull your hand away. Hours of contact at a temperature that feels pleasant is enough.

That is why body patches are formulated to run cool and slow, and why every warmer we make says the same thing on the pack: not directly against bare skin.

Use a layer, always

Hand warmers go in a glove or a pocket. Toe warmers go on the outside of a sock. Body patches stick to a base layer, never to skin.

The adhesive on our patches is chosen for fabric. It is not a skin adhesive and should never be used as one.

Do not sleep with one

Sleep removes the feedback that would otherwise make somebody move a warmer that has become uncomfortable. Warmers are for waking hours.

The same applies to anyone who might not notice: small children, and anyone whose sensation is impaired.

Reduced sensation means take advice first

Diabetic neuropathy and other conditions that reduce sensation in the hands or feet remove the warning signal entirely. Anybody in that position should speak to a clinician before using warmers of any type.

We print that guidance on the pack, in the languages you need, rather than burying it in a leaflet nobody keeps.

Disposal and storage

Spent contents are iron oxide, salt and vermiculite — non-toxic, but the sachet is a laminate and is not recyclable in kerbside paper collection.

Store sealed, cool and dry, and rotate stock by the date on the outer. A damaged outer is a warmer that has already started.