It looks like you're making compost inside of a hoop house. Does your weather get below freezing overnight right now? That could be slowing down the microbial activity.

Besides that possibility, the best way to heat up a compost pile in my experience is to turn it over and add some nitrogen to each layer as you turn it. Green plant waste, urine or animal manure is great.

If you don't have anything like that then you can use a bit of fertilizer or soaked alfalfa pellets (sold in feed stores for animals). This adds to the expense, but it does work really well.