“Jenny’s Trailer,” a yellow 20-foot-long travel trailer with the invitation to “Come Cool Down With Us” near its door, can be seen at parks and other locations in Tempe this summer. It’s part the city’s collaborative project with Arizona State University called HOPE — Homeless Outreach Prevention Effort — that is working to give the local homeless population some respite from the heat during this season of 100-degree-plus temperatures. The project enlisted the help of ASU’s Healthy Urban Environment Initiative, which then recruited a team from the Fulton Schools Engineering Projects in Community Service program to do work on the interior design elements of the heat-relief trailer.