Should you cover your pram during this summertime?

Parents have been covering their prams with blankets or thin cloths for decades, instinctively trying to shield their babies from the harmful effects of the sun as well as provide a little protection against cool breezes. But how safe is it to do this when the weather heats up?

A story from a Swedish newspaper has recently resurfaced in a number of blogs and other newspapers which suggests that this is a dangerous practice because it could lead to overheating of the pram and heat stress in the baby.

In this story, Svante Norgren, a Swedish paediatrician says, “It gets extremely hot in the pram… there is also bad circulation of air and it is hard to see the baby with a cover over the pram.”  The journalists writing the story then conducted their own experiment based on his claims and concluded that when covering a pram, there was a temperature rise in the pram and that this was because of the cover over the pram “trapping” the hot air in it. 

So what’s the truth behind this? Are the Swedish journalists right?  To find out, we need to go back to some basics.

What are the issues with babies and hot weather?

Babies and hot sunny weather don’t mix together very well. The primary advice from leading health organisations is to keep babies indoors when the sun is at its strongest -  between 11am and 5pm.

This advice is absolutely the best sun protection for babies and is important for two reasons; first because when the outdoor temperature is high, the UV level is very likely to be high too. Babies are extremely susceptible to UV exposure because they have thinner, more permeable skins that adults, so that UV rays can reach their underlying skin cells more easily. Childhood is also particularly vulnerable time for our skin; sun damage during childhood is more likely to contribute to skin cancer in later life when compared to sun damage during adulthood.

“The significant differences…between adult and infant skin suggest a greater susceptibility of infants to…penetration of UV light”
Dr. Amy S. Paller M.D

The second reason is because of the potential for babies to become heat stressed in hot weather. Babies can overheat very easily because they can’t regulate their body temperature as easily as adults can. This can lead to serious heat-related illnesses such as heat stroke.

But the problem is that it is not always realistic to stay indoors between 11am and 5pm - there are always groceries to grab, older children to collect from school and grizzly babies to entertain. There are plenty of occasions when parents will need to take their babies outdoors in our strong Australian climate.

For those occasions, is it best to cover the pram or leave it open?

What was the BIG problem with the Swedish experiment?

The Swedish journalists conducting their own experiment left a stroller facing the direct sun from 11.30am to 1pm approaching the hottest part of the day (far longer than any sensible parent would leave their baby facing the direct sun for).  They took the baseline temperature early on within that time period and then covered the pram with a thin cover and monitored the temperature rise in the pram.

The problem was that they did not report a “control” pram showing what the temperature rise would have been over that same time period if there was no cover.

The problem was that they did not report a “control” pram showing what the temperature rise would have been over that same time period if there was no cover. The temperature in a pram without a cover would have undoubtedly risen as well, as the test took place over the midday period when the angle of the sun was becoming increasingly steeper so the heat radiated from the sun that was reaching the Earth was also increasing. 

So the conclusion of the journalists’ experiment was flawed in automatically attributing the rise in temperature to the presence of the pram cover.

How did we do our testing?

Given this apparent major error in journalists’ testing and the widespread nature of the story (as well as the potentially serious health consequences for babies if parents consequently decided to remove their pram covers), we decided to conduct our own testing.

Like the Swedish tests, ours were conducted over a period of 1.5 hours of direct sunlight shining on to the strollers during a period approaching the hottest part of the day (11.30am-1pm). We recorded the temperature in each stroller every 15 minutes.

Our testing focused on covers made of natural fibres and we tested a thick baby blanket, our light layered musluv sun protection cover and a thin muslin. We also tested the temperature rise in an uncovered stroller.

What did our results reveal?

The greatest rise in temperature (by a very large margin) came from the stroller that had no cover on it.

Our tests showed one reason why it is important to cover your pram in hot weather because the greatest rise in temperature (by a very large margin) came from the stroller that had no cover on it.

The maximum ambient temperature over the midday period was reported as being 28.8°C but the sun shining directly into the uncovered pram meant that the temperature registered in the pram rose very rapidly and reached 54°C after only about 20 minutes. After that the thermometer display maxed out and started to turn black (which meant that the further rise in temperature could not be recorded). 

So does this mean that all covers are safe and never trap hot air? Unfortunately not.

These results show that whilst the Swedish journalists would have indeed observed a rise in temperature, their conclusion that it was due to the presence of the pram cover was wrong.  In fact, the opposite was true and each pram cover (to varying degrees), blocked some of the sun’s radiated heat.

So does this mean that all covers are safe and never trap hot air? Unfortunately not. The radiated heat from direct sunlight is not the only heat source you need to consider. In our next blog post, we will be looking at what factors makes an ideal baby sun shade cover for summertime and why you should still not cover your pram with an ordinary blanket or muslin.