Jeremy Hunt has launched a nationwide campaign to help parents spot the signs of sepsis.
The Health Secretary is hoping to raise awareness of the "devastating" condition which causes around 37,000 deaths each year in England.
Mr Hunt said "we need to get far better at spotting it across the NHS", adding: "By raising awareness and improving clinical practice we will save lives in the fight against this horrible illness."
The campaign, delivered by Public Health England and the UK Sepsis Trust, is part of a series of measures by the NHS to tackle the condition which arises as a complication of an infection.
It is aimed at parents and carers of newborns to four-year-old children.
Millions of leaflets urging parents to take their child to A&E or call 999 if their child is displaying symptoms will be delivered to GP surgeries and hospitals across the country.
Parents should take immediate action if their child looks mottled, bluish or pale, appears lethargic or difficult to wake, is abnormally cold to touch, is breathing rapidly, has a rash that does not fade when pressed or has a fit or convulsion.
Melissa Mead, who lost her baby son William to sepsis two years ago, will appear in a new film which forms part of the campaign.
Ms Mead said: "Sepsis is a cruel, ruthless condition which doesn't discriminate and can affect anyone. I hope this campaign reaches as many people as possible, so all parents out there know about sepsis and how serious it can be. The more parents know, the quicker they can act if they suspect their child may be suffering from sepsis – it could be life-saving.
The campaign supporter and UK Sepsis Trust ambassador added: "I will never hear my sweet child say 'Mummy I love you'. I will never know the man that William would have grown to be. So please, it is too late for me to 'think sepsis', but it's not too late for you."
Mr Hunt praised Ms Mead and other "families who have tragically lost children to sepsis" for their help with the campaign.
Sir Bruce Keogh, national medical director for NHS England said: "This campaign is an important addition to our ongoing work – we will never treat sepsis in time unless everyone 'thinks sepsis'."
Dr Ron Daniels, chief executive of the UK Sepsis Trust, said: "With sepsis claiming over 37,000 lives annually in England, this awareness campaign is a crucial step forward. Clinicians and members of the public can save thousands of lives every year if they just ask: could it be sepsis?
"The UK Sepsis Trust welcomes this initiative, but system-wide improvements to sepsis care must follow. We're delighted to have developed campaign materials that will empower parents to identify sepsis symptoms in their children and seek medical attention immediately."