What do you think is a good freed for them?
Huh? Did you mean feed? If so, compost is great plant food! If you can't make your own, you can buy it. Compost Tea is fast acting well balanced plant food. Also, if you need a different fast acting nitrogen source, fish emulsion works well, and so does blood meal. ( They both tend to gross me out, though. My mom is also vegetarian for ethical reasons. She comes over to pick what she wants, but won't if I use animal products.)
Peas are usually one of the first seeds in the ground in spring where I live. They aren't stunted by cold temps. 20 degrees C there is roughly 70 degrees here. I think that's the BEST temperature EVER for me, but it's getting warm for peas.
Did you get a nice crop from them already? If so, they may just be spent! You could try to grow another round in a shady spot, but as temps rise, they tend to peter out. If not, wait until fall brings cooler temps and try to plant again. At my house, they've been hardy even with light frosts!