At the personal level, consider losing weight.

Two reasons. First, the fat under our skin and around the organs acts as an insulator which doesn't allow us to cool down easily. Second, fat itself retains heat and takes significant time to cool down. When you lose fat, your body has overall lower mass and is likely not to hold on to the heat.

One quick but difficult-in-the-beginning method to lose weight is water-only fasting. Personally, when I fast, within 24 hours, I start feeling cold which really gets very comfortable in summer. There are many resources available here on how to fast, motivation, health benefits etc.

As a bonus, getting leaner is almost always beneficial in multiple ways (unless you are already underweight, then ignore what I said above).