The effete in the heat: heat-related hospital presentations during a ten day heat wave

Severe heat-related illness can result in hospitalisation and possibly death. These illnesses are potentially preventable; in Australia high environmental temperatures are common.

To identify (i) possible risk factors for hospital attendance with heat-related illness during a heat wave, (ii) problems with diagnosis and therapy, (iii) issues in prevention, and (iv) areas for further study.

A retrospective descriptive survey from four major teaching hospitals in Adelaide, South Australia (SA), was conducted during a ten day period of exceptional heat in February 1993, in order to review all emergency department presentations (i.e. deaths, casualty treatment or hospital admissions) with a heat-related illness as determined by attending doctors' documentation. Demographic, clinical, management and outcome data were collected.

Ninety-four patients were classified as having a heat-related illness of whom 78% had heat exhaustion. Eighty-five per cent were age 60 years or over; 20% came from institutional care; 48% lived alone; 30% had poor mobility. Peak presentation followed high daily temperatures for four consecutive days. Severity was related to pre-existing cognitive impairment, diuretic use and presenting temperature, heart rate, blood pressure, plasma sodium and plasma creatinine. Treatment tended to be non-standardised. Mortality was 12%. Seventeen per cent required a more dependent level of residential care upon discharge.

Problems were identified in accuracy of diagnosis and appropriate intervention. Awareness of the risk factor profile is needed among health workers, to ensure early preventative strategies. Populations to target for future prevention include elderly people (including those in institutional care), patients with cognitive impairment and patients taking diuretics, multiple medication and/or with other severe co-existing illnesses. Treatment could be more standardised.