Can you work at home and avoid the trip into the office? Although no maximum temperature is specified in law for comfortable working, the World Heath Organisation recommends 24C as a maximum, which might be worth mentioning to your boss. Commuting is hell if you're roasting like a pig on a spit. If you must get to the office, walk - and keep to the shady side of the street. In any case, keep a bottle of water with you at all times.

Drink

Take water breaks instead of a tea break. Because of its associations with hot countries such as India, the idea has developed that tea cools you down. This is, in fact, cobblers. Caffeine in tea (and coffee) is a diuretic and ultimately dehydrates you. Alcohol has a similar effect. So at lunch, that will be a bottle of San Pellegrino, not the Pinot Grigio.

Food

Try to eat normally, even though you might have less of an appetite, but go for foods with a high water content, such as salads and fruit.

Sprays

For people who are not content with splashing their face from the sink and don't mind parting with a tenner, various cooling sprays and "spritzers" exist. Make sure they don't contain problem ingredients such as parabens and the catch-all "parfum"; try Neal's Yard Remedies (0845 262 3145; nealsyardremedies.com), which has an aloe vera cooling spray for £6.50 and various spritzers for £10. Better still, the Mini Aeromist is a refillable pump-action water spray (£7.99, 020-7483 1991; goodhealthmatters.co.uk).

Clothing

Wear loose-fitting, light-coloured cotton clothing. Light colours reflect sunlight and natural fibres breathe rather than trap the heat. To stay cool in the current weather, less is definitely more, although some workplace dress codes are probably not up for negotiation (could barristers go wig-free, police lose their flak jackets?). But more men, for example, are starting to wear shorts and sandals to the office. If you're thinking of trying this, remember: no socks with those sandals.

Hats

Remember to cover up in sunlight: wide-brimmed hats really do make a difference. If you don't mind making a spectacle of yourself, you could try a solar-powered fan baseball cap from Solar Cool Cap, 10.50 (plus £4 p&p), 01793 752032; selectsolar.co.uk. That must be cool as in cold, not as in cool, obviously.

Home

Nice though it might be in the current conditions, air conditioning guzzles energy: according to the magazine Energy in Buildings and Industry, these cooling systems typically add 50% to the energy costs of a building. A huge investment in solar panels would be needed to power any renewable-energy air conditioning system (try the Solar Trade Association for a supplier on 01908 442290, greenenergy.org.uk), though solar-powered fans exist for small areas such as conservatories and cars (try NCL Solar nclsolar.com; or the Solar Shop, solarshop.co.uk). Well-designed new buildings use "passive solar design" techniques to help them keep warm in winter and cool in summer, but there are many ways of improving the heating and cooling performance of an existing building. These include the following:

· If you have a flat roof, consider installing a "green roof". In a nutshell, this is usually a flat roof that has been planted with some form of vegetation on top of a layer of rubble and earth. This acts as insulation, trapping heat in the building during winter and reducing the amount of sunlight it absorbs in summer. Typical planting would be wildflowers, turf or drought-loving species such as sedum. Barclays Bank has one on its new London headquarters. (More details at livingroofs.org)

· Learn from Midi France: keep south- and west-facing windows shaded during the day using external shutters, which prevent heat getting into the building. You should also keep windows closed, until the air temperature outside the house drops in the evening, because in most older, masonry buildings it is cooler inside than out; opening windows is simply letting in hot air. There are various reasons for not fitting shutters, chief among them our planning laws, so you might have to go for a compromise in louvred blinds, which will let light in but shade the room. In which case, it might be best to open a window if there is any wind, to keep the air flowing through the house. As a last resort, keep curtains drawn when the sun is on the windows.

· "Throw out all your carpets," says eco architect Bill Dunster. "They're a crap idea under any circumstances." Instead, you should expose the wood floor or maybe lay tiling: the more of the solid structure of the building you're exposed to, the easier it will be to stay cool. A carpet is creating a barrier between you and the cooling mass of the building.

· Insulate your home properly. It can slow down the rate of heat flow into it in the summer, as well as out in the winter (details of grants from the Energy Savings Trust, 0845 727 7200; est.org.uk)

Garden

A network of trellises with climbing plants will protect the house from the sun. Virginia creeper grows quickly, but can look ugly when it dies off in the winter, so you might want to go for a quick-growing evergreen such as ivy.

A horizontal pergola over any paved area near the house prevents the paving absorb heat and keeps the air surrounding the house cooler. This should be planted with a deciduous climber (wisteria, say, or honeysuckle), so light will get into the building when it dies down in winter. In the garden, a water feature not only has a cooling psychological effect, but evaporation tends to cool masonry surfaces. Solar-powered water pumps are available from the Natural Collection (0870 331 33 33; naturalcollection.com), so you've no need to feel guilty about the energy cost. The ideal is a small pool with unglazed tiles around it to absorb the water.

Beach

If all this seems overwhelming and, anyway, you've a sneaking suspicion that the heatwave won't last (this is Britain, not Bali), then head for the beach or the pool. For lidos, check out the enthusiast's website lidos.org.uk. For beaches that have come up to the Blue Flag standard for clean water, go to blueflag.org