Many areas across the US and Europe have been severely affected by continuing heatwaves.
Californians are struggling to cope with average temperatures of 100F
Extreme heat in both regions have claimed the lives of dozens of people, while power blackouts have hit many areas in the US.
BBC News website readers have been describing how they have coped with the high temperatures and blackouts.
ERICA, DAVIS, CALIFORNIA, USA
It's so horribly hot here.
The Sacramento area experienced a record-breaking eleventh day of temperatures in excess of 100F (38C) on Thursday.
At work, we're trying to conserve as much energy as possible by leaving the lights and electronic devices off.
We also close our windows and blinds and leave the air conditioning on only long enough to cool the room to a bearable temperature.
We even turned off our web servers so we wouldn't have to cool the server room.
I am worried for my family, especially my elderly grandmother.
Her house does not have any air conditioning and she is in an area experiencing the worst of the heat.
ROBERT CAILLIAU, PREVESSIN, FRANCE
It has been really bad here with constant heat over the past three weeks.
The temperature is 33C (91F) outside now, but it has regularly been in the high thirties.
I have lived in this area for 30 years and, with the exception of 2003 when it was also extremely hot, this is the worst heat I can remember.
French construction workers have found the conditions very difficult
You have to be very disciplined in this heat. I have been working hard every day to open and close shutters and windows around the house at various times to keep the temperature down inside.
You can't go outside at all during the day. People who work outside, such as construction workers have really been suffering.
They have now agreed to work from very early in the morning and finish before it gets too hot to be outside.
Friends of mine who work in Geneva, which is around five kilometres away across the border, have told me it is even worse in urban areas.
We are looking forward to some well deserved rain!
ROB BEAL, PARIS, FRANCE
The continuing heatwave has been getting really severe in Paris.
The daily norm here is 38C (100F).
It has just completely drained everyone's energy.
I travelled on the metro yesterday and the temperature reading on my mobile phone was 43C (109F).
These conditions are far too hot to be travelling in and dangerous for commuters.
STEVE NELSON, PASADENA, CALIFORNIA, USA
I'm 57 and this is the hottest summer that I can remember.
I live in San Rafael Canyon here in Pasadena and the fire danger is very high.
Eddie Climons sent in this picture of brush fires in Fresno County
Benedict Canyon, a very exclusive residential area about 15 miles away, is now on fire and threatening homes.
We normally use our air conditioning about 25 days per year, but have been using it 24/7 daily this summer, doubtless contributing to the potential blackout to the energy infrastructure.
Next week we will go to the seaside in Oregon to avoid the further affects of the heatwave.
PHILIP HARPER, CANYON COUNTRY, CALIFORNIA, USA
My wife and I are originally from Manchester, England, and right now, the wet and cold weather we left behind there some years ago sounds really good!
At the weekend, the temperature in our garden reached 112F (44C) in the shade.
Right at the moment it hit 112F, we lost all power in our area for 30 hours.
While driving around town, my car was showing an outdoor temperature of 120F (49C), which is as high as the thermometer goes.
KATRIN KELBERT, SAN JOSE, CALIFORNIA, USA
Searing heat, soaring temperatures and prolonged power outages in San Jose have made life unbearable.
Supermarkets and gas stations have closed. Ice and bottled water have been at a premium.
California is experiencing a prolonged severe heatwave
Power transformers have been blowing in the middle of the night, and there have been reports of dozens of heat-related deaths.
There is also a real sense of being at the mercy of the local power company.
Give me the relative cool and calm of England any day.
ROSCOE RAMIREZ, ORANGEVALE, CALIFORNIA, USA
We have been experiencing more than 100F (38C) temperatures in the Sacramento area for 10 consecutive days.
Together with the dry heat and pollution, most of us prefer to stay indoors.
TV stations have advertised reminders to conserve energy by postponing the usage of heavy appliances after peak hours.
Some communities have set up 'cooling centres' to try to help people avoid serious heat-related illnesses.
LEANNA TYLER, ST LOUIS, MISSOURI, USA
We have been without power since last Wednesday when a huge storm hit.
We have also been badly affected by the extreme heat. The worst days were Thursday and Friday with temperatures at 101F (38C) and a heat index of between 110F (43C) and 120F (49C).
Electric companies from seven or eight different states have come to St Louis to help restore power, yet still the progress is horribly slow.
Ice and bottled water are at a premium here. Four people have died from heat-related incidents. Two more people died from electrocution because of downed power lines.
Parts of St Louis and surrounding counties look like war zones since the storm hit. The National Guard arrived on Friday to help.
St Louis residents have tried to beat the heat any way they can
This should not be happening in 2006 in major metropolitan areas.
We have resorted to living outside like refugees, sleeping on the front porch, constantly using the water hose as the temperature in the house is over 100 degrees, and unable to cook food unless it is on the outdoor grill.
No one can understand why this is going on for such a long period.
It appears that just like with Hurricane Katrina, government red tape has delayed the process.
Heat and humidity in St Louis are nothing new - it is like this every summer. But with no way to get air conditioning or fans working it is just a horrible existence.
FRANCESCA DELLAVECCHIA, ASTORIA, QUEENS, NEW YORK, USA
After nearly seven days without power, electricity was finally restored to my apartment on Sunday evening.
It goes without saying that a week without power is frustrating.
But even more frustrating is the apparent complete lack of responsibility and accountability of the local electricity providers and the mayor's office.
The whole experience was just surreal. There were around 26,000 residents in my area without any power for a week.
Whole neighbourhoods were in complete darkness. It was unbearably hot at night.
Temperatures during the day have risen to around 100F (38C), which coupled with 80% humidity feels more like 110F (43C) degrees.
To avoid the heat in my apartment, I had to go to work very early and then go out at night to the movies or wherever I could find air conditioning.
My neighbour, who has a young baby, had to leave after the third day, she just couldn't take it any more.
The supermarkets also shut down as their food was ruined. I also had to throw out everything in my fridge.
There are still people in the area without power.
Mine has been restored, but for how long, I wonder? We were told the infrastructure was in place to deal with increased use of power during the summer months to support air-conditioners, but it wasn't there.
We still have to endure two of the hottest months in New York - August and September - what will happen then?
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