1995 Toyota Camry cooling system flush

We took our car to the shop to have it change oil, the technician recommended that our the cooling system needs maintenance. To make the story short we were able to drove it back home. Here's the sad part, as soon as my husband got to work, the car overheats.I called the shop and told the tech the sad story about what happened to our car. He said"maybe we didn't take all the air out from the radiator". Tech also said that, just make sure that there's enough water when he drive's the car back home. Unfortunately that didn't work my husband has to pull over the freeway twice in the middle of the night. This was very inconvenient for the both of us.