Yep. I lived in the middle East and SE Asia combined for around 12 years, and while occasionally it was too much, in general I loved the heat and rarely said “its too hot”, I moved back to the UK 3 years ago, in June. Hated it, was cold all the time. Now when it’s more than 25c / 77F on a calm and clear day I’m boiling and can’t sleep at night (barely anyone in the UK has ac at home).

If its head gasket I would expect the loss to be consistent. If you open the rocker cover cap / oil filling point and it looks like there is Mayo in there, then it could be a sign the head gasket is failing.

I’m afraid that your partner has a coolant addiction and you need to get them checked into rehab.

On a serious note, perhaps sitting in traffic is causing the temp to increase and causing a leak. This would make me think perhaps the radiator fan isn’t working properly?