Php编码电报机器人的字符

Hy, i have this php code for telegram bot:

  header("Content-Type: application/json");
    $parameters = array('chat_id' => $chatId,  "text" => ''  .$temp.'°C');
    $parameters["method"] = "sendMessage";
    echo json_encode($parameters);

The problem is the encode of output, this will be & deg;C, i need °C.
If I use °, the code not work.

Solved with this code:

 header("Content-Type: application/json; charset=utf-8', true,200");
    $parameters = array('chat_id' => $chatId,  "text" => ''  .$temp.'°C');
    $parameters["method"] = "sendMessage";
$parameters = array_map('utf8_encode', $parameters);
echo json_encode($parameters);