SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549
                     -------------------------------------------


                                    FORM 8-K


                                 CURRENT REPORT

                       Pursuant to Section 13 or 15(d) of
                       the Securities Exchange Act of 1934



                                 Date of Report
                       (Date of earliest event reported):

                                  May 1, 2000
                    ----------------------------------------


                                 THERMEDICS INC.
                 (Exact name of Registrant as specified in its charter)



Massachusetts                      1-9567                             04-2788806
(State or other            (Commission File Number)             (I.R.S. Employer
jurisdiction of                                            Identification Number
incorporation or)
organization)


470 Wildwood Street,
P.O. Box 2999
Woburn, Massachusetts                                                      01888
(Address of principal                                                 (Zip Code)
executive offices)

                                 (781) 622-1000
                         (Registrant's telephone number
                              including area code)









This Form 8-K contains forward-looking statements that involve a number of risks
and  uncertainties.  Important factors that could cause actual results to differ
materially from those indicated by such forward-looking statements are set forth
under the  heading  "Forward-looking  Statements"  in Exhibit  13 to  Thermedics
Inc.'s  Annual  Report on Form 10-K for the year ended  January  1, 2000.  These
include risks and uncertainties  relating to: government regulation and industry
standards,  competition and technological change,  intellectual property rights,
reimbursement by insurers for medical procedures,  medical community  acceptance
of medical devices, availability of materials and components, product liability,
international operations,  the company's acquisition strategy, and the company's
cash management arrangement with Thermo Electron.

Item 5.     Other Events

     On April 7, 2000, the Registrant issued a press release, attached hereto as
Exhibit 99, regarding its financial results for the guarter ended April 1, 2000.

Item 7.     Financial Statements, Pro Forma Financial Information and Exhibits

      (a)   Financial Statements of Business Acquired: not applicable.

      (b)   Pro Forma Financial Information: not applicable.

      (c)   Exhibits

            99 Press Release dated April 1, 2000.






                                    SIGNATURE


      Pursuant to the  requirements of the Securities  Exchange Act of 1934, the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned, thereunto duly authorized, on this 2nd day of May, 2000.

                                             THERMEDICS INC

                                             By:  /s/ Theo Melas-Kyriazi
                                                  ------------------------------
                                                  Theo Melas-Kyriazi
                                                  Chief Financial Officer







                                                                      Exhibit 99


Investor Contact: 781-6 22-1111
Media Contact: 781-622-1252


                   Thermedics Announces First Quarter Results

WOBURN,  Mass.,  May 1, 2000 -  Thermedics  Inc.  (ASE-TMD),  a Thermo  Electron
company,  today reported that revenues for the quarter ended April 1, 2000, were
$60.7  million,  compared  with $52.0  million in 1999.  Income from  continuing
operations,  which excludes the results of the company's  power  electronics and
test equipment and  heart-assist  and blood testing devices  segments because of
plans to sell these  businesses,  was $2.7 million,  or $.06 per diluted  share,
compared  with $1.7 million,  or $.04 per diluted  share,  last year.  Excluding
pretax  restructuring and unusual costs of $0.1 million in 2000 and $1.4 million
in 1999, income from continuing operations would have been $2.7 million, or $.06
per diluted share, in 2000 and $3.1 million, or $.07 per diluted share, in 1999.


Consolidated Statement of Income (unaudited)

                                                        Three Months Ended

(In thousands except per share amounts)          April 1, 2000   April 3, 1999

Revenues                                            $ 60,729        $ 51,960
                                                    --------        --------

Costs and Operating Expenses:
  Cost of revenues                                    32,245          28,018
  Selling, general, and administrative expenses       18,409          15,162
  Research and development expenses                    4,466           3,404
  Restructuring and unusual costs                         93           1,395
                                                    --------        --------
                                                      55,213          47,979
                                                    --------        --------

Operating Income                                       5,516           3,981
Interest Income                                        1,046           1,051
Interest Expense                                        (891)           (427)
Equity in Earnings (Loss) of Unconsolidated
 Subsidiaries                                             65             (21)
                                                    --------        --------

Income from Continuing Operations Before
 Provision for Income Taxes and Minority Interest      5,736           4,584
Provision for Income Taxes                             2,479           2,304
Minority Interest Expense                                566             588
                                                    --------        --------

Income from Continuing Operations                      2,691           1,692
Income from Discontinued Operations (net of
 income tax provision and minority interest
 of $1,581)                                              -               890
                                                    --------        --------
Net Income                                          $  2,691        $  2,582
                                                    ========        ========

Earnings per Share from Continuing Operations:
  Basic                                             $    .06        $    .04
                                                    ========        ========
  Diluted                                           $    .06        $    .04
                                                    ========        ========
Earnings per Share:
  Basic                                             $    .06        $    .06
                                                    ========        ========
  Diluted                                           $    .06        $    .06
                                                    ========        ========
Weighted Average Shares:
  Basic                                               41,982          41,696
                                                    ========        ========
  Diluted                                             42,981          42,806
                                                    ========        ========

     Note: The company's power  electronics and test equipment and  heart-assist
and blood  testing  devices  segments  have  been  classified  as  "discontinued
operations"  because of the company's plans to sell these  businesses.  The 1999
results have been restated to reflect this accounting treatment.


      Thermedics Inc. develops, manufactures, and markets diverse product lines,
including  implantable  heart-assist  devices  and  other  biomedical  products,
security  instruments,  and equipment that assures the quality of a wide variety
of consumer  products and bulk materials.  Thermedics is a public  subsidiary of
Thermo Electron  Corporation.  More  information is available on the Internet at
http://www.thermo.com/subsid/tmd1.html.

The following constitutes a "Safe Harbor" statement under the Private Securities
Litigation  Reform Act of 1995:  This  press  release  contains  forward-looking
statements that involve a number of risks and  uncertainties.  Important factors
that could cause actual  results to differ  materially  from those  indicated by
such forward-looking statements are set forth under the heading "Forward-looking
Statements"  in Exhibit 13 to the  company's  annual report on Form 10-K for the
year ended January 1, 2000. These include risks and  uncertainties  relating to:
government  regulation and industry  standards,  competition  and  technological
change,  intellectual  property  rights,  reimbursement  by insurers for medical
procedures,  medical  community  acceptance of medical devices,  availability of
materials and  components,  product  liability,  international  operations,  the
company's  acquisition strategy,  and the company's cash management  arrangement
with Thermo Electron.