High temperature (fever) in adults: when to get help
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 now if a fever occurs with:
Severe difficulty breathing, blue or grey lips, or severe chest pain
New confusion, collapse, extreme drowsiness, or difficulty waking
A seizure
A severe headache with a stiff neck or strong light sensitivity
A rash that does not fade when pressed with a clear glass
Confusion, fainting, or loss of coordination after heat exposure
And for anyone, someone who:
has had a seizure that will not stop, or does not wake up afterwards
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 lips or skin that look pale, blue, grey or blotchy
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 you have a temperature of 38°C or above while receiving chemotherapy, after a transplant, or when a condition or medicine severely weakens your immune system.
Follow any temperature plan given by your specialist team, as it may use a different threshold.
Same-day advice is also appropriate if you are rapidly worsening, cannot keep fluids down, are passing very little urine, or have severe pain.
Contact a clinician promptly after recent surgery if fever develops with increasing wound pain, redness, swelling, or discharge.
And for anyone, someone who:
has a fever with a stiff neck, a rash that does not fade under pressure, or severe headache
3
Does any of this apply?
Book an appointment
Book a routine appointment if the fever lasts several days without improving, keeps returning, or has no clear explanation.
Arrange follow-up if it comes with ongoing night sweats, unexplained weight loss, or other persistent symptoms.
Every sign above is quoted from the sofidex article on High temperature (fever) in adults. If you are not sure, err upward — it is always reasonable to be checked.