What are the indications for hospital referral in cases of suspected heatstroke?

Indications for hospital referral in suspected heatstroke include:

• Presence of altered mental state or new onset of altered behaviour, indicating possible severe illness.
• Signs of acute deterioration in functional ability or impaired consciousness.
• Signs of circulatory compromise such as hypotension (systolic blood pressure ≤90 mmHg or significantly below normal), tachycardia (>130 beats per minute), or poor urine output (no urine passed in previous 12-18 hours or very low urine output in catheterised patients).
• Respiratory distress indicated by raised respiratory rate (≥25 breaths per minute) or need for supplemental oxygen to maintain adequate saturation.
• Skin changes such as mottled or ashen appearance, cyanosis, or non-blanching rash.
• Any signs of shock or organ dysfunction, including decreased level of consciousness or altered responsiveness.
• Inability to safely observe the patient at home or continuing concern by the patient or carers about the severity of illness.

These criteria align with high-risk features warranting emergency hospital care to provide resuscitation and advanced monitoring and treatment facilities, as heatstroke can rapidly progress to multi-organ failure and death if untreated.

Transport should be by emergency ambulance with appropriate clinical support.

Note: While the provided guidelines do not explicitly list heatstroke referral criteria, these indications are extrapolated from NICE guidance on recognition and management of severe illness and sepsis, which share overlapping clinical features with heatstroke requiring urgent hospital care ¹.