A Rapid Intervention Team or Crew(also referred to as RIT or RIC) is a team of two or more firefighters whose job it is to rescue any firefighters in distress. Some of the standards for the RIT team are that at least two fully equipped firefighters(full turnout gear as well as SCBA and any other tools needed) will be standing by whenever crew members enter a hazardous environment.
This is the basis of the Two In, Two Out policy. Two firefighters should go in together. using a sort of buddy system, they maintain voice or visual contact at all time. if one needs to leave, they both need to. One shouldn’t stay behind. Of the two standing outside, one should be dedicated to accounting for the two firefighters inside and initiate a rescue if one of the interior firefighters is in distress. At times, another two would come on to stand by if these two are required to go in. Of course, not all departments will have enough crew members to make this possible. Sometimes there will be RIT crews at every entry point to a structure, but again, this will depend on staffing among other issues.