Possible to child proof existing pvc windows?

[Nat3kids]

I was heavily pregnant when we bought our house 2 years ago and I don’t think we were thinking too practically. Now we have very active toddler boys and i’m really nervous about them falling out of the upstairs windows if we accidentally leave them open. They are standard white pvc windows with a handle closure but it is not possible to have them tilt open at the top, as with our previous house. Do you know if we have to replace the entire window or whether some fittings can be attached to make child-safe opening a possibility?

Google window restrictors. I think they will do what you want.
We can shut our windows open a crack. Not great in high summer, but perfectly adequate the rest of the year.

We have these

2 x UPVC Window Cable Restrictor Lock with Screws Child & Baby Safety Security Wire Tested to British Standards (White) https://www.amazon.co.uk/dp/B07FLZ5465/ref=cmswwrcppapiii_ehAIFbJ6HAV2M

Thanks both, that’s really helpful! I will order some now (wish I’d done it at the start of summer

Was coming on to say exactly the same we put these in and so glad we did when we found him standing on the window ledge at 5am 🙄 We keep the keys in some as they are high enough he can't reach them to unlock.

Put your door keys on a hook high up as well high enough that they can't reach them if they stand on something (if possible) heard a noise the other day when I was washing up and found DS using a bin to stand on and to try and reach them!

We have jack locks on an the top floor windows