We determine the statistics of work in isothermal volume changes of a classical ideal gas consisting of a single particle. Combining our results with the findings of Lua and Grosberg [J. Chem. Phys. B 109, 6805 (2005)] on adiabatic expansions and com
pressions we then analyze the joint probability distribution of heat and work for a microscopic, non-equilibrium Carnot cycle and determine its efficiency at maximum power.
