A review of burn first aid treatments highlights the paucity of evidence on which to make firm recommendations. The authors recommend using cold running tap water (between 2 and 15 degrees C) and to avoid ice or alternative therapies. The optimum duration of first aid application and the delay after the injury for which first aid can still be effective are two areas of research which need further exploration.

A review of first aid treatments for burn injuries
Burns. 2009 Sep;35(6):768-75