In October it will be still very warm. You can expect some rain from time to time, because we are at the beginning of the rain season. For nocturnal trips shirts with long sleeves are fine.
The Amazon region will be very humid, but temperature rarely gets hotter than 27°C
In most lodges they accept besides the Brazilian Currency also Euros or US dollars. Changing your money into local currency is possible at the airports and in almost every city. Our guide can also take you to places where you can change money.
It is recommended to drink only bottled water. Because Brazil is a tropical country, it is very easy to quickly become dehydrated. Drink plenty of water.
A good insect repellent is very important. Also some product to reduce the results of insect bites.
Local taxis are available in most Brazilian cities of any size and most all are metered. Just make sure you always use a legitimate taxi. This is pretty easy if you have your hotel or restaurant hail or call a taxi for you (they know), only use taxis that are lined up at a ponto de taxi (taxi stand) or call a radio taxi service.
Electric current in Brazil varies widely—from 100 to 127 volts or 220 to 240 volts and from 50 to 60Hz—even within the same city, building, apartment or office. Some cities in Brazil only use 220 volts. Check the power adapters of you laptop, battery chargers and other electric appliances before you go. Many are designed to automatically accommodate input current from 110 to 250 volts while others are only for 110.