Acclimating to heat by gradually exposing your skin to sunlight can help your body adapt more efficiently, but the advice to sit in direct sun at high noon without precautions carries real risks, especially in the Netherlands where UV levels can be deceptive. A safer approach is to build tolerance through short, consistent exposure while protecting against sunburn and heatstroke.
Your body does adapt to heat over time through a process called heat acclimatization, which involves increased sweat efficiency, better blood flow to the skin, and a lower core temperature rise. However, this adaptation is best achieved through moderate activity in warm conditions, not by passively baking in peak sun. The UV index in the Netherlands can reach moderate to high levels (5-7) even on cloudy days, and fair skin types common in the Netherlands are at higher risk for sunburn and skin cancer. The advice to "kill some brain cells" is not supported by science; heatstroke can cause serious neurological damage, and deliberate overheating is dangerous.
For a practical and safe approach: start with 10-15 minutes of sun exposure on your arms and legs in the morning or late afternoon when UV is lower. Gradually increase time over two weeks, but avoid the hours between 12:00 and 15:00 when UV is strongest. Use sunscreen on your face and any areas that will burn easily. Stay hydrated with water or electrolyte drinks, not alcohol, which dehydrates you. If you feel dizzy, nauseous, or get a headache, get out of the sun immediately and cool down.
Honest tradeoffs: yes, brief sun exposure helps your body produce vitamin D and can improve mood, but the risks of sunburn, heat exhaustion, and long-term skin damage are real. The Dutch climate is humid, which makes sweating less effective at cooling you, so heat stress can build quickly. If you want to adapt, combine short sun sessions with staying in the shade during peak heat, using fans, and taking cool showers. The idea of an "outdoor sauna" works only if you listen to your body and avoid extremes.
Next steps: check the daily UV index online (from the KNMI or weather apps) and plan your exposure accordingly. Start with 10 minutes of sun on your arms and legs, then increase by 5 minutes every few days. Always wear a hat and sunglasses, and reapply sunscreen if you stay out longer. If you have a history of skin cancer or are on medications that increase sun sensitivity, consult a doctor first. This method lets you build tolerance safely without the risks of the original advice.