Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Call emergency services if clammy skin occurs with:
Chest pressure or pain, especially with nausea or discomfort in the arm, jaw, back, or stomach
Severe breathing difficulty, blue or grey lips, or swelling of the tongue or throat
Fainting, new confusion, inability to wake, or a seizure
Sudden severe weakness, very pale skin, or signs of major bleeding
Confusion after heat exposure, particularly with very hot skin
Suspected low blood sugar that does not improve or prevents safe swallowing
And for anyone, someone who:
has lips or skin that look pale, blue, grey or blotchy
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Seek same-day medical advice if clamminess is persistent or occurs with repeated vomiting, worsening fever, reduced urination, marked dizziness, or difficulty keeping fluids down.
These may be signs of dehydration or an illness needing prompt assessment.
And for anyone, someone who:
has a wound that is hot, spreading red, or leaking pus
3
Does any of this apply?
Book an appointment
Book a routine appointment if episodes keep returning, happen during sleep, interfere with daily activities, or have no clear trigger.
Also arrange follow-up if you have started a medicine and then develop troublesome sweating.
Do not stop a prescribed medicine without medical advice.
And for anyone, someone who:
has noticed a lump, a mole that has changed, or unexplained weight loss
The article also says
Do not give food or drink to someone who is confused, having a seizure, or unable to swallow safely.
Every sign above is quoted from the sofidex article on Skin - clammy. If you are not sure, err upward — it is always reasonable to be checked.