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Exertional heat illness S027

Last amended 
17 March 2022
Current RMA Instruments
SOP bulletin on new Instruments

SOP Bulletin 229

ICD Coding

ICD-10-AM Codes: T67.0, T67.1, T67.3, T67.4, T67.5 (see comments below)

Brief description

This SOP covers various heat-related health outcomes from exercise in hot conditions, typically in younger persons.  It does not cover non-exercise-related heat-induced stress/illness that typically occurs in more elderly or frail people.

Confirming the diagnosis (also see comments below)

The diagnosis is made on clincial grounds, based on the context of the injury, the signs and the symptoms.

Additional diagnoses covered by SOP*
  • heat exhaustion 
  • heat fatigue
  • heat injury 
  • heat intolerance
  • heat stress
  • heat stroke 
  • heat syncope 

* All when associated with exertion, only

Conditions excluded from SOP​
  • drug hypersensitivity reactions# 
  • exertional hyponatraemia#
  • isolated exertional rhabdomyolysis (without evidence of heat-related illness)# 
  • malignant hyperthermia associated with anaesthetic agents# 
  • neuroleptic malignant syndrome# 
  • non-exertional heat illness# 
  • pyrogenic hyperthermia# 
  • serotonin syndrome#

# non-SOP condition

Clinical onset

This is an acute "injury" that occurs at the time of the exertion in hot conditions. 

Clinical worsening

The only SOP worsening factor is for inability to obtain appropriate clinical management.  Heat syncope and heat stress/exhaustion are usually associated with complete recovery in the short term.  Heat illness and heat stroke can be life-threatening events involving organ damage and there may be serious ongoing consequences. Timely diagnosis and treatment (particularly rapid cooling to lower body temperature) is effective for reducing morbidity and mortality.

Comments - ICD codes

ICD-10-AM T67 codes cover both exertional and non-exertional forms of heat illness, with only the former covered by the SOP.

The T67 codes should be used as follows:

T67.1 Heat syncope 

T67.3 and T67.4 use for any of heat exhaustion, heat fatigue, heat intolerance, and heat stress

T67.5  Heat injury (a specific defined condition - see the SOP)

T67.0 Heat stroke 

When using any of those codes decide whether the condition is exertion related or not and only apply the SOP when it is.

Other T67 codes

T67.2 "heat cramp" - a misnomer.  Can occur at any ambient temperature.  When an isolated occurence this condition is not usually associated with a raised body temperature. This is usually a transient condition with full recovery and no dagnosis would generally be warranted. If a diagnosis is being made the term "exercise-associated muscle cramp" is preferable.  If the condition is associated with a raised body temperature then it is technically covered by the SOP definition and the SOP can be applied, but it is otherwise a non-SOP condition.

T67.6 Heat fatigue, transient - non-SOP

T67.7 Heat oedema - non-SOP

T67.8 Other effects of heat and light - non-SOP

T67.9 Effect of heat and light, unspecified - non-SOP

Comments - diagnostic labels

Heat illnesses range from mild through to severe and life threatening.  The correct terminology should be used for diagnosis.  In particular, "Heat stroke" should be reserved for the severe condition involving significantly raised core body temperature, organ damage and significant neurological impariment.  Heat stroke is life threatening and requires hospital treatment.  Heat stroke should not be confused with heat stress, the more common and milder illness.  Note also that "heat injury" is a specifically defined, serious condition involving significantly raised core body temperature and organ damage, but without neurological impariment.