Triathletes and open water swimmers competing in tropical open waters should make time to drink during long course events to decrease their core temperature and improve their speed. 

“Although it may take longer for swimmers to drink more, the time spent doing so may be compensated by an increase in swimming pace,” says a report in the International Journal of Sports Medicine.

“Increasing fluid ingestion, particularly cold fluids, during swimming in open water long-course events in hot water significantly decreases the core temperature and may prevent the hyperthermia usually seen in such competition.”