EMCC 2015 OHS Achievement Award finalist Ross Di Corleto recently posted a warning that too much fluid can be as dangerous as too little fluid on his heat stress website The Thermal Environment.
While the risk of dehydration, progressing to heat exhaustion, heat stroke and even fatality, is generally known, the condition known as hyponatraemia is lesser known but can also result in fatality.
Elevated fluid intake can result in a sodium imbalance in cells. Sodium levels can drop below the safe level of 135 mmol/L, in which case the body moves water into the affected cells to try and re-establish a balance. The cells then swell with excess water, with the brain cells being especially sensitive to this.
It should be noted that this condition is rare, but the symptoms of dehydration and hyponatremia are similar so there is a risk of misdiagnosis that can prove fatal.
Ross’ bottom line is, “… (hyponatremia) is unusual and has a much lower likelihood of occurring in hot scenarios than the risk of dehydration. So maintain fluid intake but don’t overdo it.”