Calling the fire brigade is a good option, since they're considered one of the most efficient and trustworthy institutions in Brazil. If you need urgent and immediate support, talk to the people around you. Brazilians are friendly and willing to help. They'll go out of their way to speak your language and find help.
If you've been robbed or assaulted, report it to the police. Unfortunately, you shouldn't expect huge results for your trouble. Call your embassy if your passport has been stolen or if you need help dealing with the police.
General Emergency Contacts
Federal Highway Patrol. 191.
Fire Brigade (Bombeiros). 193; www.bombeirosemergencia.com.br.
Civil Defence. 199.