The humidity in Tokyo summer is something else entirely. It's not just hot, it's like walking through soup from June to September.

What actually helps: Those cooling towels (available at any convenience store for ¥300) are lifesavers. Soak them in cold water and wear around your neck. Department stores have free cooling areas on every floor - use them.

Stay indoors 12-3pm when possible. The underground shopping areas (like Tokyo Station's Character Street) are perfectly air conditioned and great for midday breaks. Most locals avoid outdoor activities during peak summer unless absolutely necessary.