As Queenslanders are trading airconditioned spaces for backyard cricket and picnics, emergency doctors are urging them to stay hydrated this Christmas break to avoid ending up in hospital.

About 200 Queenslanders are expected to seek emergency care over the next four weeks for heat-related symptoms such as extreme dehydration, fainting, sunburn, and heatstroke.

Emergency doctors are warning Queenslanders to stay hydrated this Christmas. Credit:Unknown

The Prince Charles Hospital emergency specialist Dr Faye Jordan said some people underestimated the danger of dehydration during the Christmas break's summer heat.

"A lot of people are about to trade in airconditioned offices and sedentary activities for things like backyard cricket and the requisite beers to go with," she said.