sick cat is vomiting clear foam

My 7 year old cat starting vomiting clear foam this morning and is very sleepy and if you go near him he snarles at you and may hiss.he has vomited twice so far but is hiding at the top of the stairs.his eyes are funny looking very wide.dry nose.has been sneezing a little since he got locked outside over night 2 weeks ago.-15 below out.

Answer by Kate
Hi
well he may have cat flu or a similar cold virus which is making him feel very unwell and wanting to be left alone.

https://www.our-happy-cat.com/cat-flu.html

Or he may have a fur ball which is making him feel unwell.

https://www.our-happy-cat.com/hairballs.html

Your best option is to leave him alone for a day or so and make sure that he has plenty of fresh water available to prevent dehydration.

Keep an eye on him and if his symptoms get worse or don't seem to be easing then your vest option is to take him to the vets to find out whats wrong.

Hope he is better soon

best wishes Kate

---