I hate it when the weather is hot and the truck begins to stall. Assuming that your truck is in good running condition, the problem could be a vapor lock in the fuel line. Before we get to the cure, lets look at what causes this to happen.
Vapor lock is essentially when gasoline turns to a vapor. Not good in a vehicle since this will block the flow of fuel. In most cases, you pop the hood and let the engine cool. Once it cools down enough, you start it back up and you are on your way.
So what causes vapor lock. I have heard many folks say that it is caused by the engine heat. Well that is true - partly. The engine does contribute heat but the engine also has a cooling system which keeps the heat down. If not, the engine would overheat. The real cause is the engine compartment. Nothing is in the compartment to keep it cool hence the temperature can rise. Sure, you can vent the engine compartment but what we are trying to solve is a vapor lock.
The easiest way to prevent fuel line vapor lock is to go to the grocery store and buy a bag of wooden clothes pins. Take those pins and clamp them to various places on your fuel (specifically in the areas where it is getting hot and vapor locking). In order for the vapor lock to occur, it must heat the fuel and the fuel line to a temperature that will turn the gasoline to a vapor. By attaching the clothes pins, you are basically creating a heat sink. In order to heat the fuel and line, it must also heat up the clothes pin. It cannot raise the temperature of the clothes pin hot enough to create a vapor lock hence the problem is solved.
Ok, so this will not look real cool. Another solution is to purchase insulation for the fuel lines. This can be purchased at most racing shops. They run the fuel line very close to the headers and they get RED hot. This stuff is not cheap but it will work.
Another solution is to vent the engine compartment? How? Not really sure but if the temperature in the engine compartment stays low enough, you will not have the vapor lock either.
So what happens if the lock occurs in the fuel pump. They make insulators for those as well. Again, go to the store and purchase these blankets and it will keep it nice and cool. Remember that it is insulating from the heat inside the engine compartment and not the heat from the engine. They make these blankets for just about anything but personally, I would try the clothes pins first. You might be surprised.