1. Stay hydrated.
2. Have an ice cream cone.
3. Dismantle the fossil fuel industry which is literally burning the planet for the short term profit of a vanishingly small capitalist class.
4. Wear loose clothing.
In order to be able to do point 3,
use renewable energy.
Fly as few as possible.
Eat less meat, if you can.
Drive an electric car, it's so much more fun anyway.
Go by bike or by foot... is so much more healthy!
Try to avoid plastic as thouroughly as possible. Think also of paraffin candles: Plastic is everywhere!
Just be aware:
The small capitalist class profits from your behaviour. Change it.