News this week that two in three car seats are badly fitted combined with separate figures from local authorities that showed an alarming number of ill-fitting harnesses mean British children are at risk! The revelations have led to the call that parents’ double check the tension of car seat harnesses, particularly when their babies and toddlers wear thick coats or snowsuits as the weather turns decidedly chillier. Many UK parents don’t realise the effect that thick outdoor clothing can have on the fit of car seat harness straps or the potential consequences of straps being too loose.

According to the UK Department of Transport, 60 to 80% of all car seats are used incorrectly, with harness tension being the single biggest failing. Getting the correct harness tension is even more difficult in winter as it is hard to tell whether you have a good harness fit if a child is wearing a thick coat.

To get the correct harness tension over a puffy snowsuit or thick coat, a parent really has to tighten it substantially, which can make the child uncomfortable as their freedom of movement is restricted. Being tightly strapped in a thick coat can also lead to the child overheating once the car warms up.

To test whether you have correct harness tension when using a coat or snowsuit, you can do the two finger test:

Put the coat on the child.

Strap the child into the car seat and tighten to ensure a snug fit.

Remove the child from the car seat – without loosening the straps.

Take the coat off the child.

Strap the child back into the seat – but don’t adjust the straps.

Do the Two finger test. If you can fit more than two fingers underneath the harness at the child’s shoulder bone, the harness tension needs to be tightened or you should avoid using the coat in the car seat.

The safest bet is to strap the child into their seat correctly wearing their normal indoor clothing so you can be assured of the correct harness tension. To keep them warm before the car has had a chance to heat up, parents can place a coat or blanket over the top of their child, or use a product which is designed expressly for this purpose. The key thing is to ensure that whatever is used, still gives you easy access to the harness release button on the car seat so that they can be released easily in an emergency. You should also make sure that when you buy the car seat it is the correct one for your car and that you know how to fit it correctly in the car.