There are three areas I'd consider when introducing new team members.
1) The Work: A week is not much time to get used to working together. Pairing or group/mob programming could be a great way to bring them up to speed on the way the team works and code practices. It may slow the team down a bit for the week, but not nearly as much as trying to onboard onto a codebase from offshore.
2) The Team: If your team has a working agreement around how they communicate, definition of ready and done, code review, etc, you could share this with the new members ahead of time and then do a small recap in person. Again, this is just to avoid confusion and get conversations around that to be face-to-face.
3) Personal Connections: Like Axel's answer, give them time to create a personal connections. If your team and the new members are all ok with drinking, happy hour can be a great option. Potluck lunches can be good too - whatever fits the team's and new team members' culture. This will really pay off when conflicts arise later.