There are always at least two persons you can call in case of emergency, one is the travel consultant you are working with and the other is the tour operator who has been in co-operation with this travel consultant for the booking and service logistics. 
Those names and numbers will be provided at time of booking and you will normally find that at the bottom of the confirmed program.

See also other FAQs

What measures are in place to minimize these risks?

What vaccinations and malarial prophylaxis do you recommend?

How will the outside world be able to make contact with us?

How will we be able to make contact with the outside world?

How long will it take to evacuate an incapacitated client?

What emergency assistance (e.g. air rescue) is available, how are they contacted, and what are the estimated response times?

What arrangements (including communications) are in place for an evacuation of a client in the event of an emergency?