My husband was pulling weeds when he broke out in small red spots/fluid filled blisters and only on his upper torso. What could this be and treatment?

Poison ivy or…? There are many plants & weeds that can cause skin reactions, poison ivy being the most well-known. As long as there is no swelling of lips/throat or difficulty breathing, gently wash areas with mild soap & water to remove allergen. Use topical benadryl/aloe vera gel/ calamine lotion/ Cortaid (hydrocortisone) for rash & itching. Oral antihistamine like benadryl/zyrtec/claritin will help too. Not better—> see doc.