Ask the client if they can tell you more about this. Ask how they would rate their intent to harm themselves today, 0 (not at all) to 10 (definitely will attempt to harm myself today); ask them to rate means/plans (have they saved up pills, planned which bridge to jump off); ask them to rate preparations (have they written goodbye letters, paid off their bills, cleaned all the house). Often people will tell you that these are fleeting thoughts and they wouldn't actually do anything or act on these thoughts. Ask them about protective factors, what stops them from harming themselves. And be sure you provide them with a sheet with the local crisis numbers on it - 111, the Samaritans, etc. Tell them if that if they felt overwhelmed and that they were going to act on the thoughts, they can go to A&E. Ask them about the professional relationships they have - how is their relationship with their GP? Do they talk to their GP about these thoughts? If someone tells you they have intent to harm themselves with a high likelihood, speak to your supervisor as soon as possible - you may need to call adult safeguarding and get guidance and/or call the crisis team to intervene and/or call the police if acting on these thoughts is imminent.