Heat radiating after being parked for 2 hours?

Hi everyone,

We have a RAM 1500 Rebel 5.7 and we just had the manifolds, axels and oil pan replaced earlier today. We took the truck for a quick run to the store and back home (10 minutes to the store and 10 minutes back home). The truck has been parked for 2 hours (no garage) and there's still a lot of heat radiating out from.under the hood. We popped open the hood and everything in there was still quite hot, even the battery.

This doesn't feel normal (it never did that before) but maybe I am just being paranoid. Would someone be able to tell me what's possibly going on?

Thank you everyone for your time.