Safety and precautions

Patch-test first if your skin is at all reactive

Cut or place a small piece on the inner forearm and leave it an hour. If there's nothing beyond mild warmth and slight pinkness, you're fine. If there's itching, a raised rash or a stinging burn, this formula isn't for you — and you've found that out on a patch of forearm rather than a whole knee.

Skin rules

• Intact skin only. Never over cuts, grazes, rashes, eczema, psoriasis plaques, sunburn or recent scars.
• Never on inflamed or already irritated skin.
• Don't reapply to the same spot immediately. Rotate placement or give the area a rest day.
• Don't cut a patch to reshape it unless you're patch-testing — cutting exposes the active layer at the edge.

Handling capsicum

Capsaicin transfers from fingers to everything else and doesn't wash off with water alone. Wash your hands with soap after applying or removing a patch, before touching your face, eyes, contact lenses or anyone else. If it does reach your eye, rinse with plenty of water — it's intensely unpleasant but short-lived.

Never add external heat

Don't put a heat pad, hot water bottle, heated blanket or heat lamp over a warming patch, and avoid sunbeds and saunas while wearing one. Heat increases absorption of the active compounds and is the most common route to a genuine skin burn with capsicum products. The same applies to falling asleep on a heated mattress topper with a patch on.

Who should check with a doctor first

Situation	Why
Pregnancy or breastfeeding	Several of these botanicals, including wormwood and aconite, are traditionally avoided during pregnancy
Children	Not intended for children; skin is thinner and more permeable
Diabetes or neuropathy	Reduced sensation means you may not feel a burn developing
Circulatory conditions	Warming products affect local blood flow
Blood thinners	Worth a conversation before adding any new topical botanical
Eczema, psoriasis or known plant allergies	Higher likelihood of a skin reaction
A recent injury, swelling or a joint that's hot to the touch	Warmth is often the wrong choice in the acute phase — that needs assessing, not warming

About Radix Aconiti

Aconite root is a potent botanical with a long history in Chinese herbal medicine, where it is prepared specifically for external use in preparations like this one. Used as intended — on unbroken skin, externally, for the stated wear time — this is a well-established traditional application. Used incorrectly it is not, and that's why the standard warnings on any aconite-containing topical are worth respecting rather than skimming.

In practice this means: external use only, never on broken skin, never anywhere near the mouth or eyes, wash your hands afterwards, and keep patches — used and unused — well out of reach of children and pets. If you're at all uncertain, ask a pharmacist. They deal with this class of product routinely.

Stop using it if

• You feel burning rather than warmth
• The skin blisters, weeps or develops a raised rash
• Redness doesn't settle within a few hours of removal
• You feel unwell, dizzy or nauseated while wearing one

Remove the patch, wash the area with soap and cool water — not hot, which increases absorption — and don't reapply. Seek medical advice if symptoms persist.

And the bigger point