l had a bad ache in the middle of my chest, my left arm felt numb & my lower jaw felt numb, do you think it could have been a heat attack.

Heat or heart??? You're still here ar not you!

Why do not you visit your GP? We do not know as we do not have you in front of us with a Cardiogram and the necessary expertise.

If u still have these symptoms u need to seek medical advice from a more appropriate source than this, as yes it may well be indicative of a heart problem. Even if they have since eased off, u should still phone ur nearest medical centre or NHS Direct, an ECG will detect if u have had a mild heart attack.
While l applaud this site for enabling people to discuss their health, l would wish that people who think they have a serious & potentially life threatening condition brewing, would speak to proper medical experts, rather than well meaning & variably experienced contributors to YA.

Yes it could have been minor one. Any chest pain should be treated as suspicious and a visit to a doctor is a must for you. 12 hours after a heart attack, no matter how small, a blood test will confirm or otherwise and it is a positive result. No gray area a straight yes or no. It could be brought on by the heat but you MUST have a check up.
Best of luck.

If you are in the UK, you may still be able to talk to someone at your GP surgery to ask advice.
If they are closed now, phone NHS Direct and speak to one of the trained nurses. Phone number is 0845-4647

Heart attack is diagnosed by three ways.
(1) By symptoms. The health care provider will perform a physical exam & listen to ur chest using a stethoscope. The doctor may hear abnormal sounds in ur lungs (called crackles), a heart murmur, or other abnormal sounds.
You may have a rapid pulse. Blood pressure may be normal, high, or low.
(2) ST elevation in Electrocardiograph.
(3) Blood tests can help show if u have substances produced by heart tissue damage or a high risk for heart attack. These include:
* Troponin l & troponin T
* CPK & CPK-MB
* Serum myoglobin
Take ECG & consult a Cardiologist. If heart attack has taken place, u should reach the the nearest hospital within 45 minutes.

Your symptoms project a typical case of impeding heart attack. You may please consult your cardiologist and go for an ECG immediately under your his advice to confirm the condition. Your BP and blood sugar levels are also important.
A sublingual tablet of sorbitrate 5mg, under your cardiologist supervision, also may help to clinch the diagnosis.