It is important that you consider your level of fitness before deciding which trek to go on, as the condition in the Cordillera Blanca can be rather extreme. In addition to long days of hiking, sometimes you will have to deal with extremely cold weather – the Andean Summer being the winter months in Peru and temperatures at night going as low as -15C. In addition, remember that you will be hiking at high altitude and do not ignore altitude sickness symptoms, as the consequences can be serious. If you are not a strongly experienced high-altitude hiker, always hire a guide; and if you set off on your own, make sure that you are aware of all weather conditions and possess the necessary equipment/supply to last you several days.