Multiple files using template.ParseFiles in golang

Question

For example.go, I have

package main

import "html/template"
import "net/http"

func handler(w http.ResponseWriter, r *http.Request) {
    t, _ := template.ParseFiles("header.html", "footer.html")
    t.Execute(w, map[string] string {"Title": "My title", "Body": "Hi this is my body"})
}

func main() {
    http.HandleFunc("/", handler)
    http.ListenAndServe(":8080", nil)
}

In header.html:

Title is {{.Title}}

In footer.html:

Body is {{.Body}}

When going to http://localhost:8080/, I only see "Title is My title", and not the second file, footer.html. How can I load multiple files with template.ParseFiles? What's the most efficient way to do this?

Thanks in advance.