Abstract

Heat health responses for young children constitute a unique public health challenge and Oral Rehydration Solution (ORS) have emerged as a key intervention in various advisories and heat action plans HAPs). ORS is an extraordinarily impactful first-line therapeutic intervention in reducing mortality and morbidity on account of dehydration and dyselectrolytemia in children caused by acute diarrheal diseases and is backed by state health and non-health agencies the world over. The reconstitution of ORS into a solution for oral rehydration therapy relies on the packaging instructions and frontline health workers; systematic reviews highlight low levels of knowledge and understanding of these aspects. Most of these HAPs and advisories are conspicuously silent on reconstitution and dosages. We have drawn upon available global literature and Indian evidence to shape this discourse across three strands – policy perspectives, clinical evidence and critiques on inappropriate usage of ORS and mislabeling of rehydration fluids to shape our arguments. It is imperative that only WHO formulated ORS is used for this purpose. Heat Action Plans need to specify age- and weight-specific ORS guidance, in line with the UNICEF advisory. India’s linguistic diversity calls for multilingual and pictorial instructions for correct preparation by caregivers, Capacity building of first responders and frontline health workers to correctly administer ORS for children’s HRIs is also an urgent imperative.

Physiological heat vulnerabilities for children

Infants and young children have specific heat-related physiological and behavioral vulnerabilities: (i) children produce more heat per kilogram of body weight; (ii) younger children have a higher surface area-to-mass ratio and absorb more heat from the environment; (iii) children have lower sweat rate per gland and begin to sweat only at a higher body temperature; (iv) infants experiencing heat stress have less capacity for regulating their temperature independently; (v) infants and young children have poorer blood circulation and lower proportional cardiac output and therefore are unable to adapt quickly to changes in temperature; and (vi) children tend to spend a lot of time outdoors and inadequately replenish fluid loss sustained during prolonged exposure and playing, leading to exertional heat illnesses. There are clear associations between pediatric emergency room visits and extreme heat events, mostly on account of dehydration, electrolyte disorders, gastrointestinal infections, and exacerbations of bronchial asthma.

Dehydration in the context of HRIs is generally assessed by urine color or volume but a robust point-of-care test to detect/measure dyselectrolytemia is not available. Consumption of plain water quenches thirst and provides short-term relief during dehydration but excessive heat leads to further water loss. ORS, an iso-osmolar glucose-electrolyte solution with base and citrate, helps replenish fluids and electrolytes lost due to sweating by helping the body absorb fluids more efficiently, thereby balancing the electrolyte levels and restoring homeostasis.