How can I safely transport cooked food in warm weather? I've a factory of 300 people and I serve them lunch everyday. At the moment the kitchen is adjust-en with the factory but I have to move the kitchen asap to a place around 20kls. far from my factory. The big problem is I'm not sure how to deliver them from my kitchen to factory. I like to box every meal separately. At summer the temperature is 40+ C outside and my concern is will the food be safe to travel from kitchen to factory without getting spoil. Do I need refrigerated vans and if then how will I be able to warm them up ? I will be using stainless steel contains to carry the foods. Please advice.
With all cooked, perishable food the total time in the so-called "danger zone" 40-140 °F / 4-60 °C must be minimized to avoid growing bacteria and thus food-borne illnesses. (Your transporting plans place your dishes flatly in the danger zone, so not a good idea.)

If your kitchen is on site, this is typically done by keeping food hot between cooking and serving. With many dishes this can be done for a short time only (a few hours maximum) before quality decreases.  

If cooking off-site on a comercial scale, there is often the "cook and chill" process used. 
In short, food is cooked, then cooled down rapidly to refrigerator temperature. It is transported cold to the cafeteria and reheated there in special ovens, hot water bath or simply on a stove.

Prepared food can be stored for up to five days, but you need special cooling/heating equipment and cold storage/vans.
(A manufacturer's explanation here.)