I've just had a Dermaquest Pumpkin Peel and then was exposed to quite strong sun. Is this OK?

Yes you better avoid sun direct exposure and sport / sweating for a while. Because peeling is aiming to exfoliate the old skin, so your skin become more sensitive after peeling.

We must consider skin after peels as thinner than it normally is therefore all beauty professionals always applying high spf after treatment. I personally advice my clients to not to go to swimming pools as chloride in the water can irritate the skin.

Typically after a peel of any kind one should not expose their skin to direct sun light for any long periods of time. This should have been explained to you by your professional with your aftercare instructions. I hope however, that sun protection was adequately applied to your skin, post peel.