What you should know about altitude sickness. sometimes people get sick at high altitudes, such as in the mountains. This is called mountain sickness or high-altitude sickness. Contrary to common belief there are no specific factors such as age, sex, or physical condition that correlate with susceptibility to altitude sickness. Some people get it and some people don't, and some people are more susceptible than others. Lack of oxygen causes high-altitude sickness. As altitude increases, the air becomes "thinner," which means less oxygen is in the atmosphere. You get less oxygen in your lungs with each breath, so the amount of oxygen in your blood declines. All people can experience mountain sickness, but it may be more severe in people who have heart or lung problems. Symptoms usually begin within 48 hours of arriving at high altitude. The higher the altitude, the greater the effects. People can notice effects when they go to an altitude of 2.500 to 3.000 meter. If you have heart disease (such as heart failure) or lung disease (such as emphysema), you may have symptoms at lower altitudes.

Symptoms include: Headaches, breathlessness, fatigue, nausea or vomiting, inability to sleep, swelling of the face, hands and feet.

Both heart rate and breathing rate increase as the body tries to send more oxygen to its tissues. At very high altitudes, body fluid can leak into the brain (called brain or cerebral edema) or into the lungs (pulmonary edema). Both these conditions can be serious or even life-threatening. The best way to avoid or lessen the effects of mountain sickness is to increase altitude slowly. Climbers and hikers can take two days to reach 8,000 feet, and then another day for each 300 to 500 higher meter. This may not be an option for people who travel to a destination at high altitude. Most people can adjust or "acclimatize" to the high altitude within a few days. Short activities in the Huaraz Region.

The weather conditions in Peru - Huaraz, the Sierra is a mountainous zone of the country that extends from north to south in the middle and high zones of the Andes mountain range. Within the geography of Peru constitutes a natural region. It limits to the west with the region of the Coast and to the east with the Forest. To the north it has continuity with the Inter-Andean Region of Ecuador and to the south with the Andean Region of Bolivia and Chile. For that reason the weather conditions in the city of Huaraz on the 3200 meters is different to any region of the country.

April to October: Cordillera’s dry season offers the best trekking and climbing conditions

The dry season is marked by clear sunny days and cold nights due to the lack of clouds. This also makes it the best season for trekking and climbing as the views become even more spectacular and the night skies filled with stars. Rain can occur but is very limited and mainly concentrated at night in this season. By the end of the dry season the vegetation can become somewhat browner as the drought has had its toll. During the day you can expect blue skies pretty much of the time. Since we are close to the equator and very high up, the sun can be very strong so always bring sun protection block, a hat and sunglasses. It is comfortable to trek in shorts and t-shirt. However when the sun goes in it can get cold very quickly so always have a warm jacket, fleece and long pants close at hand. You also need a good 4-season sleeping bag at night and a warm jacket, woolly hat and scarf.

December: A relaxed postseason atmosphere.

Some years the rain can start as early as October. However usually we just get a couple of heavy showers each week and the rest of the time it is sunny or overcast. The rain just lasts for a couple of hours and dries up pretty quick. Good gear for rain is

January to March: Wet and rainy, but appropriately geared trekkers enjoy the silence.

In the wet season, Huaraz weather is as you would expect is quite wet. In the beginning of the wet season this will be mainly during the day, but by January and February these showers can last for almost all day. In the beginning and end of the rainy season, the sun does shine often and views can be equally spectacular due to the clouds playing through the highest peaks. In this season the nights are less cold but due to the rain the temperatures can drop rapidly now and then. The wet season can last until the end of March. January, February and March are at the height of the wet season. During these months you can expect rain at any time. Bring good waterproof clothing, pack your sleeping bag within several plastic bags, and bring sun protection block and a good hat. In fact prepare for just about all four seasons in one day. Huaraz is generally very quiet during these months.