Professor Mike Tipton, from the Extreme Environments Laboratory at the University of Portsmouth, has this advice for staying cool, hydrated, and safe during a heatwave

Mike Tipton

10 min read

Food and drink

  • Stay hydrated. Drink plenty of water or non-alcoholic and decaffeinated fluids, even if you don’t feel thirsty. Use the colour of your urine to guide whether you’re hydrated enough - light straw coloured is fine.

  • If you can’t do without a pint in the sun, drink some water at the same time to stay hydrated. Avoid dehydrating liquids, like alcohol and caffeinated drinks which increase the metabolic rate (heat production). They are also diuretics, which cause your body to remove fluids from your body at a quicker rate than other liquids.

  • Eat hydrating foods high in fibre and natural juice like watermelon, strawberries, tomatoes and bell peppers. Keep them in the fridge and also eat cooling snacks like popsicles, or slightly frozen grapes. Slushies are a good way of cooling down, as the phase change from ice to water absorbs the body’s heat. Dehydration can lead to heat exhaustion, if this happens stop all activity, seek shade and cool with fans and misting the body with water. Eat smaller meals, and avoid heavy foods, as easy-to-digest foods require less work from your body.

You and your body

  • Learn the signs and symptoms of overheating, which include light-headedness, rapid pulse, pins and needles in the fingers and mouth, cramps, nausea and vomiting and headache. Don’t ignore it, act as soon as you see the signs.

  • Keep an eye on older people you know. Be careful with children; they heat up quickly.

  • Sweat. You can create artificial sweat by spraying your skin with fine mist from a simple garden spray. Then a fan can be used to enhance evaporation and cool down your skin.

  • Allow the physiology of your body to keep delivering heat to the skin surface and then take it away with immersion of fanning. Aggressive cooing will close skin blood vessels and “trap” heat in the body. Hand and foot immersion in cold water help cool the body when hot. Tepid showers also work.

  • Slow down. 80% of the energy consumed during exercise is released as heat. So, restrict strenuous activities, or schedule them to a cooler time of the day (e.g. early morning).

  • Avoid sunburn.

Around the house

  • Keep the house as cool as possible by keeping shades and drapes closed during the hottest part of the day on the side of the house facing the sun. When the outside air cools to a lower temperature than inside - usually in the evenings - open up the windows and dry and promote air movement though your accommodation. Use fans if you have to. Air condoning helps but adds to the climate change problem causing the problem in the first place – natural processes are better.

  • Turn off tech. A surprising amount of heat is generated from appliances in the house, so turn off the ones you’re not using and avoid charging devices close to your bed overnight. Conventional incandescent light bulbs also radiate heat. So, keep as many as you can switched off, or if you’re able, switch to low-energy light bulbs. Check on other equipment like smart speakers and TV casting devices, which might be in direct sunlight for long periods of time and may need to be switched off to prevent overheating.

  • Keep your fridge cold. A fridge with a temperature above 5°C could compromise the food inside. The fridge needs to work harder in hot weather. If yours is overheating, ensure you keep a window open to allow for good airflow. And when putting in food, leave enough room for air to circulate around the fridge’s interior - if the appliance is crammed with groceries, cold air will not be able to circulate fully. Be aware that if the fridge is not as effective as usual, meat, milk and the like will go off sooner than normal.


On the road

  • It takes very little time for a car to get too hot for children and animals. Keep car keys out of children’s reach, and teach children to honk the horn if they get stuck inside.

  • Don’t set off straight away. Driving inside a hot vehicle could leave you feeling disoriented or light-headed. Spend a few minutes with the doors and windows open, and use the aircon to lower the car’s temperature.

In the bedroom

  • Help your bedroom to breathe. Light-coloured cotton is the best material for bed sheets and pyjamas during warmer nights, as it’s more breathable than satin and silk.

  • When you’re too hot, and especially before bed, have a tepid shower a shower around 30°C is better than a cold shower.

  • Use a fan in the bedroom to help keep you cool at night.

  • If there are cooler areas of your house (e.g. downstairs), sleep there.


  • Cooling animals by giving them a cold bath or shower will keep their body temperature down. Make sure they have plenty of water to drink too.

  • Don’t forget to protect their pads as pavements and roads can become hot enough to burn their skin.

  • Signs of heat stroke in a pet include rapid panting, drooling, vomiting and twitching muscles. Seek help or take-action at the first signs.

Dog at the beach

Article originally published in The Mirror.