What about adding Honey, or Agave ?

Had this same problem once. Used the salsa as a cooking sauce over baked chicken (pieces). The result was "fire chicken" -- now the chicken was too spicy to eat. So, shredded the chicken and used as a burritto base -- all the other burritto stuff (lettuce, tomatoes, sour cream) calmed down the fire chicken and the result was the best (per family) ever. It has now become a standard.

Wow, 5 jalapenos is a lot for the size of this recipe. I would think 2-3 would be closer to the mark. I agree with the others - if you make the recipe again without the chiles and then add the two results together, it would probably be just right.

You could split it in two and had another can of tomatoes to half (maybe a smaller can to start). Then what about cooking up some tomatillos and putting in the other half for a different flavor profile. If you puree them, it would be a fairly good freezer item for the extra.

I would use it as a chunky hot sauce. Use it to spice other items as needed. You could mix a bit into sour cream to create a dip. You could add a bit to scrambled eggs or an omelet. You could season chili with it. You could puree it as previously suggested and use it to season everything from etouffee to curry.

Ooo...yes to the avacado....and the more tomato...thanks friends.

Or you could change it up ... if you are serving right away you can add some diced avocado which will cool it and add another texture too!

I think the best bet, like Amanda says, is to go for dilution. To keep the seasoning the same, you could make another batch of salsa sans jalapenos and then mix the two together. Or, cook the salsa a little: to soften the ingredients. Puree the bejeezus out of it and use it as a fresh hot sauce.

Tough call.

Boil some diced potato and let them soak in the mix awhile could absorb some heat then remove. And try to pick out the pepper bits with chopsticks.
Make it more..with more stuff.

Do you have anymore tomatoes in the house? If so, I'd add your salsa to the tomatoes, a little bit at time, until you have a salsa that has better heat balance. You may need to adjust some of the seasoning (lemon juice, cumin, etc).