Help with keeping bedroom cool?

[TheOpportuneMoment]

We have constant issues with keeping my toddlers bedroom cool. The second the sun comes out it's impossible to manage. It's February and his room is currently 24 degrees. He still naps and even with the door open to the hallway he wakes up sweaty and grumpy. The rest of the house is a normal temperature, I'm wearing slippers and a jumper downstairs.

His room is quite small and south facing. Last year we spent about £300 on a portable condenser air con thing, which does literally nothing at all. I think it makes it hotter. He won't sleep if there's a fan on, the room is tiny and even the silent one is too loud and too close to his bed.

We've tried keeping the windows closed and blinds down, but that just turns the whole window into a giant radiator.

I've seen there are reflective window films you can put on, but would they just reflect the light straight back at our opposite neighbours?

Any tips for anything that's worked would be much appreciated! In the height of summer his room gets up to 33 degrees by the evening and is a constant source of stress, so I want to try and find a way of managing it now.

@JeezusHChrist

"look into changing his roller blind for proper shutters"

Will make no difference Op. waste of money. Blind can be pulled up and shutters opened. Much of a muchness.

Slatted blinds or shutters let draught through, roller blinds don't - well, not without flapping around. As PP said, you need windows open both sides of the house to get a through draught.

Temporary fix but freeze a hot water bottle to put in his bed for nap times and night times when it gets warmer. Let him sleep under just a duvet cover, no duvet, if you aren't already doing this.

Do you have blackout blinds ? Some are supposed to keep the heat out as well as the light.