This week, the UK has been experiencing bouts of hot water, with temperatures predicted to reach 34C in the coming days.
Britons have been urged to stay safe in the heat, taking protective measures when spending time outdoors in the sun.
Amid the heatwave, Britons unused to the scorching weather will need to take precautionary measures to ensure they don't suffer from heat exhaustion or heatstroke.
If an individual's body is unable to cool down and they develop heatstroke, then their health could be at serious risk.
So, how can you spot the signs of heatstroke and how can you treat it? Here's everything you need to know.
What is heatstroke?
Heatstroke, otherwise known as sunstroke, occurs when a person's body temperature has become overheated to a harmful degree, St John Ambulance explains.
An individual may develop heatstroke if they've been suffering from heat exhaustion.
When a person spends too much time in the sun or in hot temperatures, they may become too dehydrated.
At this point, they may stop sweating, which means their body will no longer be able to cool itself down. This can result in them developing heatstroke.
If an individual experiencing heat exhaustion is able to cool down within 30 minutes, then their health shouldn't be at serious risk, the NHS states.
However, if they develop heatstroke, then an ambulance should be called on 999 or 112.
What are the symptoms?
Symptoms of heat exhaustion include experiencing a headache, dizziness, loss of appetite, nausea, excessive sweating, cramping, an increased heart rate, a temperature of 38C or above and feeling very thirsty, the NHS outlines.
Adults and children who experience heat exhaustion tend to exhibit similar symptoms. However, children may also appear sleepy.
If a person displaying these signs hasn't improved within 30 minutes, then their condition may have developed into heatstroke.
Symptoms of heatstroke include lack of sweat even if they feel very hot, a temperature of 40C or above, shortness of breathe, confusion, experiencing a seizure, losing consciousness and becoming unresponsive.
How can you help someone experiencing heatstroke?
If you spot that someone may be suffering from heat exhaustion, then they should be moved to a cool environment, the NHS advises.
You should do all that you can to help them cool down, including ensuring that they drink lots of water, cooling their skin with a spray or sponge and having them lie down with their feet slightly raised.
If they haven't improved in 30 minutes and you believe they may have developed heatstroke, then an ambulance should be called on 999 or 112.
While waiting for the ambulance to arrive, St John Ambulance recommends trying to cool them down by either wrapping them in a cold wet sheet or sponging them down.
If their temperature appears to go back to normal, then replace the wet sheet with a dry one.
As you wait for the arrival of a paramedic, keep checking their breathing, pulse and level of response, St John Ambulance says.
If at any point they become unresponsive, then you must check their breathing and ensure their airway is open.
For more information on how to look after a person who has become unresponsive, click here.
How can heatstroke be prevented?
There are certain measures you can take to prevent heat exhaustion and heatstroke in hot temperatures, the NHS states.
These include drinking lots of cold drinks, bathing in cool water, wearing loose clothing, avoiding the sun during peak sun hours and not drinking too much alcohol.
The NHS advises keeping a close eye on those who may be more susceptible to heat exhaustion and heatstroke, including children, older individuals and those who have long-term health conditions.
For all the latest news on the UK weather, click here.