Trying to keep your house bearable — and get any sleep — as Swansea Bay bakes under a red extreme heat warning? You are not alone.
The Met Office says overnight temperatures may not drop below 20C in parts of Wales this week, making it one of the hardest spells of the year to sleep through.
Wales has already provisionally recorded its highest June overnight temperature on record, with the mercury staying at 20.3C at St Athan, in the Vale of Glamorgan, on Monday night.
So here is a round-up of the advice that actually works — drawn from experts we have spoken to in previous heatwaves.
Keep the heat out during the day
It feels counterintuitive, but throwing the windows open in the middle of the day often makes things worse, letting hot air pour in.
The trick is to keep curtains and windows closed during the hottest hours, especially on south-facing rooms, then open up at opposite sides of the house in the cooler early morning and late evening to get air flowing through.
Let the hot air escape
Heat rises and gets trapped on upper floors — exactly where most people are trying to sleep.
Opening the loft hatch gives that hot air somewhere to go, drawing it up and away from bedrooms.
Switch things off
Televisions, games consoles, computers and even phone chargers all give off heat, as do ovens, dishwashers and washing machines.
Switching electricals off, and running big appliances early in the morning or late at night, keeps that warmth out of the living space — and trims the energy bill.
Swapping traditional bulbs for LEDs helps too, as older incandescent bulbs throw out most of their energy as heat.
Make a fan work harder
A freestanding fan costs only pennies to run overnight, and there is a simple way to get more from it.
Position it in front of an open window once the outside air has cooled, so it draws the cooler air in and pushes it through the room, rather than just circulating warm air.
Green it up
Houseplants can take the edge off a stuffy room through transpiration, the process by which they release moisture into the air.
Snake plants, peace lilies and spider plants are all good choices, while shrubs and planting outside can help shade and cool the house too.
And the tip that sounds all wrong: take a hot bath
It seems mad in this weather, but one bathroom expert has previously argued that a hot bath is the best way to cool down and drop off to sleep — and that a cold shower can actually backfire.
The reasoning is that very cold water makes the body fight to keep its core temperature up, leaving you feeling hotter afterwards.
A warm bath, by contrast, is said to stimulate the body’s own cooling system, helping heat escape and lowering body temperature in time for sleep — an idea echoed by sleep researchers, who note some people fare better with a warm bath when a room is very hot.
There is more detail on the home-cooling tips here, including advice on ventilation systems for the longer term.
Whatever you try tonight, the heat is expected to peak on Wednesday and Thursday before easing towards the weekend.
