It can be very difficult to know what to bring with you for trekking, but there are actually pretty strict dresscodes at play. For one, it is of vital importence that you bring with you long socks so that you can tuck in your pants into your socks. This is because there are fireants in the jungle, and they can leave a pretty nasty bite.
Furthermore, it can get very hot in Uganda, but it can also rain a lot. And you will be sitting still for an hour when looking at the gorillas, and this can make you very cold. Especielly considering the climate is rainy, humid and at an high elevation. You should therefore go for layers, a nice t shirt with a thin longsleeved t-shirt, and a rain jacket is what I opted for, and it was perfect in my opinion. It is important to be prepared for any kind of weather, as you may be walking in the jungle for hours before spotting the gorillas, and the weather can shift quickly.
In addition to this, sometimes you will not be on any trails at all. You will be stepping over bushes, twigs and leaves at an unpaved path with just the rangers paving the way with a machete. You should leave your fancy clothes at home, and wear something that makes it easy for you to move, that you’re comfortable in, and that you’re not concerned with ruining.
It is a requirement to wear long sleeves and long trousers, preferably in black, neutral or khaki colours (i.e. no bright colors). You should also wear good waterproof hiking shoes. Proper footwear is crucial. Also consider taking with you some gloves, a rainjacket, and a hat.