Climbing high altitude peaks without oxygen tanks is extremely dangerous and is not recommended, as the lack of oxygen can lead to serious health problems such as mountain sickness, cerebral edema or pulmonary edema. However, if you are in an emergency situation, the following measures may help improve acclimatization, but they are not a substitute for professional mountaineering equipment and measures: 1. **Gradual acclimatization (altitude training)**: Gradually increase the time you spend at high altitude so that your body can gradually adapt to the lower oxygen levels. Ideally, train at lower altitudes first. 2. **Stay hydrated**: Dehydration will worsen altitude sickness, make sure you drink enough water. 3. **Nutrient intake**: High altitudes require more energy, make sure you have enough carbohydrates and proper caloric intake in your diet. 4. **Slow down**: At high altitudes, move as slowly as possible and be careful not to overexert yourself. 5. **Medication help**: Some medications such as acetazolamide (Diamox) can help the body adapt to high altitudes faster, but they should be used under the guidance of a doctor. 6. **Deep breathing exercises**: Use deep breathing exercises to improve the efficiency of your body's oxygen supply. 7. **Get enough rest and sleep**: Make sure you get enough rest and sleep during your climb to help your body recover. 8. **Recognize the symptoms**: Be aware of the symptoms of mountain sickness, such as headaches, nausea, and fatigue, and descend immediately if you experience these symptoms. 9. **Travel with experienced climbers**: Travel with experienced climbers who can provide valuable guidance and support. Remember, high-altitude climbs without additional oxygen are fraught with risk and should only be used as a last resort and require adequate preparation, planning, and training. Always prioritize safety and if you feel unwell, you must immediately evacuate to lower altitudes.