I am going on the Hola Peru tour departing 21st December. We will be trekking the Inca Trail in early January, but I am very confused about what sort of clothing I need to take. I was going to buy some zip off walking trousers, but I'm not sure whether I need lightweight ones because I'll be hot walking, or whether it will be cold due to the altitude - can you give me some idea of the sort of temperature in comparison to the UK. I know it will be cold at night so I need a good sleeping bag etc, but does it get much warmer during the day, or will it be cold the whole time? Want to make sure I buy the right sort of stuff!