Swedish weather agency SMHI has a yellow warning for high temperatures in large parts of southern Sweden, with predictions that it may soon be over 30 degrees in some areas.
If you're affected, here are five key tips for coping with the heat.
Stay indoors
Staying inside where it is cooler is particularly importantly in the middle of the day when the sun is at its hottest. Indoor temperatures are often lower and there is always shade. Draw down blinds and bring in air from windows at night, when it is cooler.
Drink water often
The body loses a lot of fluid when it gets hot and you sweat, so regular water intake is important.
If you get dehydrated, it becomes more difficult to maintain a steady blood pressure, which carries a risk of get kidney and heart failure, and/or fainting.
Dress cool
Wear loose, light-coloured clothing made of materials such as cotton or linen. If you have to go outside, wear a hat and sunglasses for extra protection.
Cool down whenever possible
It may seem obvious, but doing what you can to lower your body temperature is important when you feel too hot. Taking a cold shower, placing a damp towel over your neck or wrists, or dipping your feet in cool water are all good options.
Be alert
Watch out for warning signs of heatstroke, especially in the elderly or young children. These may include increased heart rate and breathing rate, dizziness, or unusual tiredness. A dry mouth and reduced urine volume may be signs of dehydration.
Sweden's crisis information site has further tips and details on how to protect yourself and others in the heat.
You can also read some tips from The Local's readers, many of whom come from climates warmer than Sweden's is typically.
Scientists have shown that recurring heatwaves are a clear marker of global warming primarily caused by burning coal, oil and gas – and warn they are set to become more frequent, longer and more intense.