Band & Brown has been drafted in to increase the number of 11- to 16-year-olds with first-aid skills.
The agency was recruited following a four-way pitch. The overall brief is worth £580,000, of which PR is valued at £120,000.
The 15-month campaign will centre around PR creatives, media partnerships, digital advertising and social media - all supported by the 'Life. Live It' schools drive. The activities will launch on World First Aid Day on 12 September.
Band & Brown CEO Gill Brown said: 'We are looking forward to challenging young people's perceptions of what it means to learn first aid and be willing and able to use it.'
The agency will report to British Red Cross campaign manager Paul Donnelly.
The initial brief explained that the objective was to 'measurably increase the number of children and young people in the UK who are confident, competent and willing to act when they find themselves, their family or friends in a crisis that can be helped by first aid'.
Band & Brown will also provide pro-bono support to mental health charity Mind, after 70 health and wellbeing charities applied to be considered for the offer of free PR help.
The Taking Care of Business campaign will seek to eradicate negative attitudes towards mental health in the workplace.