The planet is seeing extreme temperatures with more than a thousand record breaking temperatures recently. This will be detrimental to your health, and potentially your finances due to higher utility bills to keep your home cool.
There are other factors depending on where in the planet you are. Extreme heat and humidity are a combination for human disaster, and it is already at a point where people are being hospitalized or dying from this. I hate to say this, but we cannot reverse climate change as the catastrophic damage has already been done.
How do you prepare and survive in this sweltering heat?
First and foremost, stay indoors. Direct sunlight is good until the temperatures rise above 100 degrees F (about 38 degrees C). If you cannot be indoors, stay in the shade. Second, stay hydrated. This is crucial as dehydration will incapacitate you. Other things that can be done would be get a shemagh. Covering your head with this will keep you slightly cooler. Better yet, wet the shemagh and wrap it around your head and neck. It will keep you even cooler.
Shelter is key if you are adventuring outdoors or in a survival situation. Your shelter must be well shaded inside and allow for air to flow through. A better form of shelter would be a cave provided there is ample air inside (some caves have lower oxygen content as you go deeper into it.)