Requires a Dummy account
Open the command console: ESC > Gear Icon > Under the keyboard tab select Advanced > Check off Enable Developer Console
Press the ` button to open the console and type:
map ctf_2fort; hostname "boost"; sv_lan 0; sv_cheats 0; (I had to input this twice to be detected on my LAN for some reason)
That will create your match. Choose Pyro on the Red Team. Then type the following command:
mp_teams_unbalance_limit 0; mp_idledealmethod 0; mp_idlemaxtime 0;
Make the Dummy Account a Sniper. Lower his health to the point that the after burn damage will kill him but the initial attack would not. I think around 30HP should be efficient. Light him on fire for a a second and quickly headshot the Pyro. If you do it right, you will die and the burn damage will kill the Dummy account.