For most children, falling over, getting into scrapes and arguing in the playground are all part of the rough and tumble of day to day life.
But as four-year-old Morgan Taylor starts school, his parents fear that the stress of such routine experiences could kill him.
Morgan suffers from a rare condition called adrenal insufficiency, which means he cannot naturally deal with physical or emotional setbacks.
His body does not produce the stress hormone cortisol, and so his body will begin to shut down if he is not administered a life-saving injection within 30 minutes of any stressful event.
His dad Neil, 37, explained: "If you or I fall over, our body will deal with the stress of that situation, but Morgan's body can't do that.
"Even if he had an argument with someone, he wouldn't be able to sit down and calm himself down. He's just not capable.
"Any kind of shock to the system, physically or emotionally, means he needs a cortisol injection as his body won't naturally release it.
"If he doesn't get the injection, his body will start to shut down and he becomes clammy, lethargic and run down and he would eventually die.
"We have to take his kit wherever we go as just a trip to the park or the shops can be dangerous."
Morgan was diagnosed with the condition after being born by emergency Caesarean at 28 weeks, weighing just 1lb 8oz.
When he was a week old, he contracted an infection in his bowel and his mum Susan, 39, and dad Neil, were told to expect the worst by doctors who said he was not strong enough to survive.
Susan, a mother-of-five, said: "They sent us home for the night to be with our other children and said they would call as soon as he started to deteriorate.
"It was so upsetting to be told our baby wasn't going to last the night.
"We had only had him a week and I hadn't even been able to give him a cuddle."
But amazingly, the call never came and the couple returned to the hospital the following morning to learn that their little boy was pulling through.
However, Morgan has been left with adrenal insufficiency which makes him vulnerable to physical and mental stress. Other symptoms of the condition include fatigue and muscle weakness, dizziness, nausea, loss of appetite and stomach ache.
Susan has stayed at home to look after Morgan, who also has growth problems, chronic lung disease, a heart defect and behavioural problems.
But he has now started school and she said: "I worry about him and he's in a class with other children who are much bigger than him. He has to really think about what he's doing.
"He knows all about his condition and he knows what the injections are for.
"He's aware that he has to be cautious and knows he's not allowed to play contact sports. We have had to drill it into him."
All of the staff on the school premises are trained to administer cortisol injections to Morgan if he needs them.
"I feel more comfortable because of that," said Susan.
"All the staff came forward to be trained which is nice because they didn't have to.
"But I can't help but worry that everything will be OK as he has complex medical needs, just like any parent would.
"He's very happy and incredibly cheeky, and although he's got this illness we just have to deal with it.
"It's heart breaking really because he's always got a smile on his face no matter what.
"We don't know what the future holds for him but while he's happy that's all we can ask for."