Written with people moving from Turkey in mind. The Portuguese rules still apply more broadly.
The Portuguese Sun: A Warning
The UV index in Portugal can reach extreme levels (10+) in summer. Sunburn can happen in less than 20 minutes. Health authorities recommend avoiding direct exposure between 11:00 and 17:00.
Always wear sunscreen, even on cloudy days. Pharmacies sell high-quality sunblock (Protetor Solar). Skin cancer rates are rising, so take the "Portuguese lunch break" seriously and stay in the shade during peak hours.